LA LIGNE FINE PAPERS N°18 : Political Polarization. The Transformation of Democratic Conflict into a Crisis of Legitimacy

Executive Summary

Political polarization is one of the main transformations of contemporary democratic systems. It cannot be reduced to the intensification of ideological disagreements or the rise of radical political formations. It refers to a set of processes by which political preferences are structured into antagonistic collective belongings, reciprocal perceptions between groups deteriorate, and the institutions responsible for organizing democratic competition can gradually lose their common legitimacy. This evolution raises a fundamental difficulty: while democracy is based on the recognition of pluralism and the possibility of permanent confrontation between competing political projects, its functioning also requires that actors accept collective rules regardless of the results they produce.

Political conflictuality is not, however, a democratic anomaly. Representative societies have historically been built around religious, economic, territorial, social and cultural divisions. These oppositions have contributed to the emergence of political parties, the organization of social movements and the formation of institutional compromises. Polarization becomes problematic when disagreements cease to be perceived as legitimate divergences and turn into antagonisms in which opponents are seen as threats to the existence or future of the political community. Electoral competition can then evolve into a confrontation in which defeat becomes difficult to accept and the preservation of common institutions takes a back seat to the victory of one’s own side.

This transformation must be understood from several distinct dimensions. Ideological polarization refers to the distance from political preferences; affective polarization refers to hostility between partisan groups; institutional polarization arises when trust in procedures, public authorities, and checks and balances becomes strongly conditioned by political affiliation. These dimensions may reinforce each other, but they are not necessarily simultaneous. One society may experience deep programmatic oppositions while preserving recognized institutions, while another may exhibit high partisan hostility despite limited divergences on certain public policies^[1].

The causes of polarization are multiple. Economic transformations, territorial inequalities, cultural evolutions, the recomposition of party systems and the strategies of political leaders contribute to the formation of new antagonisms. Digital environments contribute to modifying the circulation of information, the visibility of controversies and the modalities of mobilization, without constituting a sufficient explanation on their own. Empirical research thus invites us to go beyond the idea of a polarization mechanically produced by algorithms to study the interactions between collective identities, institutions and political ^[2]behaviors.

The consequences go beyond electoral competition. Sustained polarization can make it difficult to form majorities, increase negotiation costs, reduce the continuity of public policies, and weaken trust in institutions. It becomes particularly worrying when citizens tolerate attacks on democratic principles by representatives of their own camp, because they see the victory of their opponents as a greater threat^[3].

Polarization thus acquires a strategic dimension. In societies facing major industrial, energy, technological and geopolitical transformations, a state’s ability to act also depends on its ability to produce collective decisions that are legitimate enough to be applied and maintained. Political fragmentation can then become a constraint on the continuity of public action and the mobilization of national resources.

This Paper defends a central proposition: political polarization becomes a strategic vulnerability when it transforms democratic competition into a confrontation over the legitimacy of adversaries and common institutions. Democratic resilience therefore does not depend on the absence of conflicts, but on the ability to preserve rules that are sufficiently recognized to allow political coexistence, alternation and collective action.

Introduction: Democratic Conflict and Polarization

Contemporary democracies seem to be confronted with a growing contradiction. The technical possibilities for political participation, expression and mobilization have never been so diversified, while the capacity of societies to organize lasting disagreements appears to be weakened in several national contexts. Citizens have greater access to information, political leaders can communicate directly with their constituents, and public controversies benefit from permanent visibility. However, this multiplication of spaces for expression does not necessarily translate into improved mutual understanding or a strengthening of trust in institutions. It can also accompany an intensification of antagonisms, a fragmentation of interpretations of current events and an increased contestation of the legitimacy of opponents.

Political polarization occupies a central place in this transformation. It is frequently invoked to explain the difficulties of governments, the rise of protest formations, the tensions surrounding elections or the deterioration of public debate. However, its extensive use can lead to the grouping of different phenomena under the same concept. The fragmentation of a party system, the radicalization of a discourse, the increase in institutional mistrust and hostility between voters are not necessarily the manifestations of a single process. Their distinction is essential to understand the mechanisms of democratic weakening and to identify the conditions under which institutions manage to preserve their functioning.

Democracy cannot be defined by the absence of conflict. On the contrary, it is based on the recognition of legitimate divergences between citizens and on the existence of procedures for organizing their confrontation. Elections, parliamentary debates, social mobilizations and public controversies are instruments for representing and regulating these disagreements. A society in which political preferences are uniform would not necessarily be more democratic. Pluralism presupposes that individuals can defend contradictory interests, challenge the decisions of their representatives and propose alternative orientations.

The difficulty arises when political antagonisms begin to change the conditions of this coexistence. In a functioning democracy, adversaries can defend incompatible projects while reciprocally recognizing their right to participate in competition. Institutions then ensure that the victory of one side does not remove the possibility of future alternation. When this recognition weakens, the competition can evolve into an existential confrontation in which each group considers that the victory of the other would permanently compromise the values, interests or identity of society.

Jennifer McCoy and Murat Somer have proposed the concept of pernicious polarization to characterize situations in which societies are structured around mutually antagonistic camps and where political divisions tend to absorb other dimensions of collective life. This approach highlights the role of leadership mobilization strategies and delegitimizing dynamics in transforming existing cleavages into lasting oppositions^[4].

The issue then goes beyond the quality of public debate. Polarization can affect trust in electoral procedures, the independence of checks and balances, the formation of compromises and the ability of governments to maintain certain policies in the long term. It can also transform the conditions under which citizens interpret judicial decisions, statistical information or administrative interventions. An institution may no longer be evaluated according to its mandate and guarantees, but mainly according to the consequences of its decisions for the different political camps.

This study therefore examines the mechanisms by which polarization is formed, reinforced and can become an institutional vulnerability. It distinguishes its ideological, affective and institutional dimensions, analyzes the social and informational transformations that contribute to its development, and then studies its consequences on democratic governance and the state’s capacity for action. Based on a comparison between several national configurations, it finally proposes a reflection on the conditions of democratic resilience by 2035.

The guiding question is: under what conditions does political polarization cease to organize democratic pluralism and become a factor of social fragmentation, institutional paralysis and strategic vulnerability?

Political Polarization: A Transformation of Historical Forms of Conflict

Democratic societies have always been structured by deep divisions. The formation of contemporary states, the extension of suffrage, industrialization and the transformation of social relations have produced sometimes particularly intense conflicts around property, work, religion, sovereignty and the organization of institutions. These oppositions have contributed to the construction of party systems and the consolidation of representative mechanisms. They have also demonstrated that democratic functioning does not presuppose the prior existence of a social consensus, but the ability to transform antagonisms into politically organized conflicts.

The institutionalization of conflict was one of the main innovations of representative regimes. Political parties made it possible to aggregate social interests, elections established competitive procedures for the exercise of power, and assemblies provided spaces for confrontation and negotiation. These institutions never eliminated fundamental divergences between groups. They nevertheless made it possible to express themselves in a framework where political defeat could remain temporary and where collective decisions were likely to be revised during subsequent alternations.

Contemporary polarization must be distinguished from this ordinary conflictuality. It arises when political preferences tend to be structured around relatively stable oppositions and when distances between groups become central to the way citizens interpret public life. This evolution may concern programs, social representations or reciprocal perceptions between voters. It does not necessarily constitute a homogeneous process: the different dimensions of polarization can evolve at different paces.

Ideological polarization refers to the distancing of political positions on one or more axes of competition. It can concern the redistribution of wealth, the role of the state, immigration, civil liberties, sovereignty or environmental policies. An increase in this distance may make certain compromises more difficult, but it is not enough to characterize a democratic crisis. Voters can support highly differentiated programs while accepting the rules allowing their opponents to come to power.

Affective polarization concerns another dimension. It manifests itself when citizens develop a marked preference for members of their own political group and hostility towards those who belong to competing groups. Disagreements are then no longer only about the policies proposed, but also about the qualities attributed to the people who defend them. Party affiliation can become a criterion of moral, social or intellectual judgment, independently of individual behaviour.

Andres Reiljan’s work shows that this affective polarisation exists in European party systems and that it cannot be reduced to an American particularity. His comparative analysis underlines that affective antagonisms can reach high levels in multiparty democracies, which invites us to distinguish the structure of electoral systems from the intensity of feelings between political groups^[5].

The contemporary transformation of political conflict is also due to the possible superimposition of several cleavages. When social affiliations, cultural preferences, territorial trajectories and partisan identities converge towards relatively coherent oppositions, disagreements become more difficult to compartmentalize. A divergence on public policy can be interpreted as the expression of a more general antagonism between conceptions of society. The possibility of building alliances that vary according to the subjects can then diminish, since each compromise risks being evaluated as a concession granted to a group that is globally opposed.

This dynamic changes the political meaning of decisions. Economic reform no longer represents only an orientation that can be discussed on the basis of its costs and benefits. It can become a symbol of victory or defeat for groups that identify with antagonistic collective projects. Political leaders can then encounter difficulties in negotiating agreements that are compatible with some of their programmatic preferences, because cooperation with the adversary involves a high symbolic cost.

The notion of deleterious polarization developed by McCoy and Somer makes it possible to understand this change in nature. The authors show that certain dynamics of polarization lead to a structuring of society around antagonistic camps that perceive each other as threats. The strategies of leaders can contribute to this evolution when they transform social divisions into exclusive political oppositions and encourage the delegitimization of adversaries^[6].

However, it is important not to consider any strong opposition as a deleterious polarization. A democratic society must allow the expression of radical criticism and the defense of profound transformations of its institutions. The decisive distinction concerns the relationship to common rules. A political force can challenge the economic organization, propose a constitutional reform or defend a strategic break while recognizing the political rights of its opponents. Conversely, an apparently moderate discourse can contribute to a dynamic of delegitimization if it systematically presents certain groups as deprived of the right to participate in competition.

Polarization thus becomes problematic not when it makes disagreements visible, but when it reduces the ability of actors to recognize the legitimacy of those who carry them. This distinction forms the basis for the analysis of contemporary mechanisms of political fragmentation.

The Transformation of Partisan Identities and the Rise of Political Hostility

Political affiliation is not only an expression of a rational preference for a programme or candidate. It can also become an important dimension of social identity, through which individuals interpret their relationships with other groups and their place in the political community. Parties, movements and ideological traditions provide collective benchmarks, historical narratives and representations of the public interest. This identity function contributes to democratic mobilisation, but it can also reinforce antagonisms when political groups are defined primarily by their opposition to each other.

Affective polarization is based on this transformation of party affiliation into a social boundary. Individuals may develop positive feelings towards members of their own group and attribute negative characteristics to people identified with competing formations. The political opponent then ceases to be the defender of a questionable orientation and becomes the representative of a set of values, behaviours or intentions deemed incompatible with those of the group to which they belong.

This mechanism can influence the way information is interpreted. When a political identity becomes particularly important, criticism of a party or leader can be perceived as attacks on the group to which the individual belongs. Questionable behaviour by representatives of one’s side may be subject to more lenient interpretations, while comparable actions by opponents are assessed more severely. The coherence of collective identity may thus take on greater importance than the examination of particular situations.

Affective polarization can also alter relationships between citizens. Political preferences become likely to influence interpersonal trust, perceptions of competence, and willingness to cooperate. When partisan groups are associated with distinct social or cultural characteristics, political antagonisms can extend beyond election periods and affect interactions that do not directly affect public decisions.

This development should not be confused with the existence of strong political identities. Parties play an essential role in the representation of interests and democratic participation. They allow citizens to identify with collective projects and to organise themselves to defend their preferences. A democracy without party loyalties would not necessarily be more stable or more representative. The risk arises when political identification becomes sufficiently exclusive to reduce the mutual recognition of groups and make compromises socially costly.

The comparative literature also emphasizes that affective polarization does not mechanically depend on ideological distance. Reiljan’s work shows that multiparty systems can experience significant hostility between political groups, while national configurations vary according to party structures and relations between electorates. The intensity of programmatic disagreements does not, therefore, in itself allow the level of affective mistrust to be deduced^[7].

One of the major consequences of this distinction concerns the possibility of compromise. In a mainly programmatic competition, an agreement can be evaluated according to its effects on public policies. In a competition with a strong identity, cooperation with the adversary can be interpreted as a form of betrayal, regardless of the content of the agreement. Political leaders can then be encouraged to favor confrontation to preserve the loyalty of their electorate.

The dynamic can become cumulative. Hostile rhetoric reinforces the negative perceptions of opponents, while these perceptions increase receptivity to confrontational messages. Policymakers may then consider that the radicalization of the attitudes of their supporters justifies even more antagonistic mobilization strategies. Political groups are not necessarily equally responsible for this evolution, but their interactions can contribute to reinforcing it.

The main democratic challenge thus lies in the distinction between the defence of one political identity and the negation of the legitimacy of other identities. A society can tolerate strong party affiliations as long as they remain compatible with the recognition of pluralism. Polarisation becomes a vulnerability when membership of a political group gradually determines the judgement made on the very legitimacy of its opponents.

The structural and political determinants of contemporary polarization

Polarization results from the interaction between social transformations and political strategies. Economic developments, cultural changes, territorial recompositions and mutations of party systems can create lasting tensions, but these tensions do not automatically translate into hostility between groups. Their transformation into political antagonisms depends on the way in which the actors interpret, organize and mobilize them in electoral competition.

Economic transformations are a first factor. The globalization of trade, industrial change, automation and the recomposition of labor markets produce differentiated effects according to territories and social categories. Some populations benefit from new professional opportunities, while others may experience a deterioration in their economic prospects or a loss of stability. These differences affect not only income, but also representations of social mobility and confidence in the ability of institutions to guarantee satisfactory living conditions.

When economic hardship is interpreted as the consequence of political decisions favouring certain groups to the detriment of others, it can fuel long-term antagonisms. Political competition then becomes a space in which feelings of injustice, downgrading or exclusion are expressed. However, this dynamic is not inevitable. Inequalities can also lead to redistributive demands, trade union mobilisations or institutional compromises. Their polarising effect depends on the organisations and discourses that give them political significance.

The territorial dimension sometimes reinforces these mechanisms. Differences between metropolises, rural areas, intermediate cities and former industrial areas may concern access to public services, transport, higher education and professional opportunities. When these differences are perceived as manifestations of a political hierarchy between territories, they can promote a feeling of relegation. Political leaders can mobilise these perceptions by contrasting the interests of certain areas with those of other territorial categories.

Cultural transformations constitute a second set of factors. Debates about immigration, national identity, social norms, religion or intergenerational relations touch on fundamental conceptions of society. They can become particularly polarizing when they are presented as irreversible choices between incompatible collective models. Citizens may then see a political defeat as threatening not only their immediate interests, but also the transmission of their values and the continuity of their way of life.

Demographic and generational transformations can also alter political balances. Successive cohorts do not have the same economic, cultural, or technological experiences. Their preferences may differ on redistribution, environmental policies, social norms, or the organization of work. These differences do not necessarily produce opposition between generations, but they can become mobilizing resources when they are integrated into antagonistic political narratives.

Policymakers’ strategies play a decisive role in transforming these tensions into lasting polarization. Leaders select the issues they want to make visible, build electoral coalitions, and propose interpretations of social challenges. They may seek to bring together groups with different interests or, on the contrary, accentuate divisions that can mobilize their electorate. McCoy and Somer thus emphasize that deleterious polarization can be fueled by political strategies that present adversaries as fundamental threats and structure competition around an opposition between mutually exclusive groups^[8].

Electoral incentives can reinforce these behaviours. In certain configurations, intensely mobilising an already acquired electorate may appear more advantageous than seeking compromises likely to convince hesitant citizens. Political leaders can then favour confrontational messages, especially when they consider that their supporters expect firm opposition to their opponents. Polarisation thus becomes an instrument of mobilisation and loyalty, whose immediate electoral benefits may outweigh the long-term institutional costs.

This interaction between structural factors and political strategies explains why polarization cannot be reduced to a mechanical consequence of inequalities or cultural transformations. The same social difficulties can produce different political responses depending on the institutions, party traditions and the behaviour of leaders. The analysis must therefore focus as much on the social conditions under which cleavages form as on the political mechanisms that transform them into antagonisms.

The transformation of the information space and the role of digital platforms

The development of digital platforms has profoundly changed the conditions for the circulation of political information. Citizens have greater access to content, public officials can communicate directly with their constituents, and controversies benefit from permanent visibility. The boundaries between journalistic information, political commentary, partisan communication and individual expression have become more difficult to distinguish in certain digital spaces. This transformation creates new opportunities for participation, but it also modifies the mechanisms for selecting and amplifying messages.

Platforms can help increase the visibility of conflicting content. Political controversies generate reactions, comments and shares that can increase their circulation. Policymakers can use these mechanisms to mobilise support and maintain a permanent presence in the public space. Users can also select sources that match their preferences, which can limit their exposure to certain competing interpretations.

However, it would be insufficient to mechanically attribute polarization to algorithms. Political preferences often pre-exist digital exposure and individuals may voluntarily seek content that confirms their beliefs. Traditional media, social relations and partisan strategies also continue to structure perceptions. Platforms therefore operate in a political environment that is already organized around cleavages, which they can make more visible or reinforce depending on the circumstances.

An experimental study published in Nature in 2023 provides important insights. Conducted among 23,377 American Facebook users during the 2020 presidential election, it reduced their exposure to content from politically related sources by about a third. This intervention changed their information environment, but produced no measurable effect on the indicators of affective and ideological polarization studied during the period under consideration. The authors emphasize that these results do not exclude long-term cumulative effects or the influence of other mechanisms specific to the platforms^[9].

These results suggest that several phenomena can be distinguished. Content selection corresponds to the information that users choose or are led to access. Amplification refers to the mechanisms that increase the visibility of certain messages. Persuasion refers to the ability of content to change preferences or attitudes. Finally, mobilization refers to its influence on political behavior, in particular electoral participation or activist engagement. These dimensions can interact, but they should not be confused.

Disinformation is an additional challenge. It can contribute to the dissemination of unfounded accusations, to weaken the credibility of institutions and to reinforce the negative perceptions of adversaries. However, informational fragmentation is not limited to the circulation of false content. Citizens can access accurate information while attributing different political meanings to it. Polarisation can therefore persist even when the facts are available, because disagreements also concern their interpretation and the trust placed in the institutions that produce them.

The V-Dem Institute has identified worrying relationships between polarization, disinformation and autocratic processes. Its 2025 report noted a significant increase in polarization in 45 countries, 24 of which had reached levels described as « toxic » according to its indicator. The institute also highlighted the frequent association between government disinformation, polarization and the degradation of certain democratic guarantees. These observations must be interpreted according to V-Dem’s own definitions and measurement methods; they do not demonstrate that a single factor would explain all the changes observed^[10].

The strategic issue concerns the ability of societies to maintain spaces for discussion in which disagreements can be formulated on the basis of verifiable information. This requirement does not imply the existence of a single interpretation of events. It implies that controversies can be examined according to criteria that are sufficiently shared to allow contradiction. When any information becomes suspect because of its political origin and the institutions responsible for producing the facts are systematically considered partisan, the capacity of public debate to arbitrate disagreements is reduced.

The responses to this transformation must therefore go beyond the mere regulation of digital content. They also concern the transparency of platforms, the independence of information, the quality of public data and the possibility for citizens to verify political claims. Reducing informational vulnerabilities does not consist in eliminating controversies, but in preserving the conditions in which they can be debated without leading to a general delegitimization of sources and institutions.

Institutional polarization and the weakening of democratic legitimacy

Democratic stability rests on a fundamental distinction between the legitimacy of institutions and the approval of the decisions they produce. A citizen can consider a law to be bad while acknowledging that it was adopted according to due process. He can challenge a judicial decision without denying the authority of the judiciary or oppose a government without questioning its temporary right to exercise power. This distinction allows divided societies to maintain common rules despite sometimes deep disagreements.

Polarisation becomes particularly worrying when this institutional recognition deteriorates. Public decisions can then be evaluated mainly according to their partisan consequences. An institution that adopts a decision unfavourable to a political group can be accused of bias regardless of the procedural guarantees respected. Conversely, questionable behaviour can be tolerated when it is committed by representatives of its own camp. Institutional trust gradually becomes conditioned by political affiliation rather than by the recognition of common rules.

Milan Svolik’s work helps to understand this mechanism. His analysis shows that polarisation can reduce voters’ ability to punish politicians who undermine democratic principles when these officials also defend their partisan preferences. Citizens can then be faced with a trade-off between preserving democratic rules and winning their own side. When antagonisms are strong enough, some people favour the latter to the detriment of the former^[11].

This dynamic is particularly vulnerable because it can reduce the electoral costs of institutionally questionable behaviour. Politicians may have an incentive to weaken checks and balances or challenge procedures when they believe that their constituents will continue to support them. Polarization can thus turn partisan loyalty into a political resource to justify attacks on democratic guarantees.

Institutional mistrust can reinforce this evolution, but is not equivalent to it. The results of the OECD survey on the determinants of trust in public institutions, published in 2026, show a disconnect between the recognition of the usefulness of voting and the feeling of being able to influence decisions. In the countries studied, 68% of respondents consider that voting can have a moderate or important influence on government action, but only 31% believe that the political system actually allows people like them to have a say. These results are not a direct measure of polarisation, but they document a sense of low influence that can fuel challenges to representative institutions^[12].

Institutional trust also depends on political affiliations. Citizens may evaluate the same institutions differently depending on whether or not they support the officials who lead them. A certain gap between the majority and the opposition is an ordinary feature of democratic competition. The difficulty arises when this gap becomes large enough to call into question the recognition of institutions regardless of the electoral results.

Institutional polarization can then produce a cumulative dynamic. Mistrust of political leaders favors the reception of discourses challenging their legitimacy. These discourses reinforce the negative perceptions of opponents, while institutional decisions are interpreted through partisan affiliations. The credibility of institutions gradually decreases, which reduces their ability to arbitrate conflicts and can fuel new contestations.

However, this development is neither automatic nor irreversible. Transparent procedures, independent checks and balances, appeal mechanisms and the possibility of regular alternations can help to preserve the recognition of common rules. Institutions must also remain open to criticism and reform. Challenging a judicial decision, an electoral procedure or a public policy can be fully legitimate when it is based on verifiable arguments and is within the guarantees provided by law.

The decisive distinction therefore concerns the criteria for contestation. An institutional critique contributes to democratic functioning when it makes it possible to identify errors, irregularities or inadequacies. It becomes problematic when it is based on the idea that any unfavourable decision constitutes, by definition, proof of illegitimacy. In this case, the institutions gradually lose their ability to be recognised as common arbiters.

Polarization as a strategic vulnerability of public action

The consequences of polarisation go beyond electoral competition and the quality of public debate. They can also affect the conditions under which institutions produce decisions, mobilise resources and conduct public policies. This dimension is particularly important in societies facing transformations that require long-term investments, particularly in the fields of defence, energy, infrastructure, education and research.

The first possible consequence concerns the formation of majorities. In parliamentary systems, the ability to govern often depends on negotiations between several political parties. These negotiations can become more difficult when cooperation with an opponent involves a high electoral or identity cost. Parties may refuse to support a measure compatible with part of their preferences because its adoption would be interpreted as a victory for the opposite camp. Affective polarisation can thus reduce the space for politically acceptable compromises.

In presidential systems, the consequences can take a different form when the executive and the assemblies are controlled by opposing forces. Institutional control mechanisms, designed to limit the concentration of power, can become blocking spaces when actors persistently refuse to negotiate. However, it would be excessive to attribute any governance difficulties to polarization. The absence of a stable majority can also result from substantial programmatic differences, electoral fragmentation, or particular institutional rules.

The second consequence concerns the continuity of public policies. Many strategic policies have their effects over horizons that go well beyond the duration of a mandate. The construction of energy infrastructure, the development of military capabilities, the transformation of education systems or reindustrialization require successive investments and relative predictability of orientations. When alternations are accompanied by a systematic questioning of previous policies, administrations, companies and local authorities may encounter more difficulty in planning their commitments.

This continuity does not presuppose the absence of alternation. Democracy makes it possible to modify political orientations precisely when voters want a change. The strategic question is rather to distinguish between objectives requiring institutional stability and instruments that can be revised. A democracy can maintain long-term commitments while organizing intense competition over their modalities. Polarization becomes restrictive when it transforms each change of majority into a general questioning of previous decisions, regardless of their effectiveness or necessity.

The third consequence concerns the credibility of administrations. Public policies are based on institutions whose missions go beyond immediate partisan preferences. Statistical services, health authorities, tax administrations, courts and control bodies must be able to produce decisions that are recognised according to professional and legal criteria. When their action is systematically interpreted through political competition, their ability to intervene can be affected. Citizens may challenge the information they disseminate, while politicians may be tempted to reduce their autonomy or question their impartiality.

The fourth consequence concerns the capacity for collective mobilization in the face of crises. Emergency situations frequently require cooperation between institutions, politicians, administrations and citizens. A highly polarized society may find it more difficult to produce a shared interpretation of the situation or to accept measures with immediate costs. However, this difficulty depends on the type of crisis, the trust placed in the relevant institutions and the behaviour of leaders. Some external threats may temporarily strengthen cooperation, while others themselves become objects of partisan confrontation.

The relationship between polarization and policy capacity must therefore be seen as conditional. Strong political oppositions can improve oversight of government action, expose neglected issues, and prevent the adoption of policies that are insufficiently debated. Democratic conflict has a key remedial function. Vulnerability arises when antagonism permanently reduces the ability to take and implement regularly adopted decisions, and to maintain the commitments necessary for the continuity of the state.

In a context of budgetary constraints, technological competition and international tensions, this dimension acquires particular importance. Public power does not depend solely on its financial, human or industrial resources. It also depends on its ability to organize collective decisions and to maintain them long enough for them to produce their effects. Polarization thus becomes a strategic variable when it modifies the political cost of public action and reduces the predictability of the State’s commitments.

Differentiated national trajectories: United States, Europe, Brazil and France

International comparison shows that polarization does not produce the same consequences everywhere. The differences are due to electoral systems, party structures, the behaviour of leaders, institutional traditions, and the resources available to counter-powers. The same intensity of partisan hostility can therefore result in different political configurations. Above all, comparative analysis makes it possible to avoid considering American polarization as the universal model from which all other democracies should be interpreted.

The United States is nevertheless a particularly important case. The structuring of the competition around two major parties favours the identification of relatively stable camps. Political controversies can be quickly integrated into a general opposition between Democrats and Republicans, while presidential elections concentrate a strong symbolic dimension. This organisation does not make polarisation inevitable, but it can accentuate its effects when partisan identities are superimposed on cultural, territorial and social divergences.

One of the things that Svolik’s work is about why party loyalty can, in certain circumstances, compete with the defense of institutional principles. When voters see their opponents’ victory as a major threat, they may become less willing to sanction questionable behavior by their own representatives^[13].

European democracies have more diverse configurations. Multi-party systems sometimes allow for the formation of variable coalitions, but they can also produce lasting antagonisms between several political families. The existence of a large number of parties is therefore not a guarantee against affective polarisation. Reiljan’s research shows that hostility between voters exists in many European systems and that it should be studied from the relations between partisan groups rather than through a simple opposition between two blocs^[14].

Brazil illustrates another configuration, in which political confrontation has been articulated with controversies over electoral procedures and the legitimacy of institutions. The tensions surrounding the 2022 presidential election and the attacks on federal institutions on January 8, 2023 have shown that polarization can go beyond electoral competition to directly affect the acceptance of results and the authority of institutions. V-Dem’s 2025 report points out, however, that Brazil has also experienced a reversal of some autocratic trends, notably through institutional defense mechanisms and the fight against electoral disinformation. This case is a reminder that a dynamic of polarization does not necessarily lead to irreversible degradation and that institutional responses can alter its trajectory^[15].

France has a particular configuration, in which partisan fragmentation, institutional mistrust and the recomposition of cleavages overlap without being equivalent. The transformation of the party system, which has become particularly visible since the 2017 presidential elections and reinforced by the 2024 legislative elections, has changed the conditions for forming majorities and parliamentary negotiations. But the existence of several electoral blocs is not enough to demonstrate an increase in affective polarization. This must be measured on the basis of reciprocal perceptions between voters and the way in which antagonisms influence political behavior.

The results of the CEVIPOF Political Trust Barometer, published in February 2026, nevertheless provide a worrying diagnosis of the relationship between citizens and national institutions. Only 22% of French respondents say they trust politics, while trust in political parties reaches 15% and trust in the National Assembly 20%. Trust in mayors remains significantly higher, at 60%, and trust in several protection and public service institutions also remains high. The contrast suggests that French mistrust does not uniformly concern all institutions, but particularly affects actors involved in national political competition^[16].

The same barometer shows that 82% of respondents continue to consider democracy to be a good system of government. This data is fundamental to the interpretation of the phenomenon. Mistrust of politicians and representative institutions does not necessarily reflect a rejection of the democratic principle. It can also express dissatisfaction with the practical functioning of the system, the quality of representation or the ability of governments to meet expectations^[17].

The French case thus invites us to distinguish several dimensions. The fragmentation of the party system complicates certain institutional negotiations. Mistrust of national leaders weakens the perception of political representation. Ideological and cultural antagonisms can reinforce oppositions between electorates. But these phenomena should not be grouped under a single category without examining their causal relationships. Polarization is one of the possible components of a broader crisis of legitimacy, without exhausting the explanation.

The comparison between these different configurations leads to an essential observation: polarization does not automatically produce the same effects depending on the institutions that frame it. Electoral rules, the solidity of counter-powers, the ability of parties to negotiate, and the attitude of leaders towards their opponents can mitigate or amplify its consequences. The strategic question therefore concerns not only the intensity of divisions, but the mechanisms that allow a society to continue to function in spite of them.

Possible trajectories of polarization by 2035

Contemporary political transformations make it possible to envisage several trajectories without assuming that polarization will follow a linear progression everywhere. Comparative experiences show that antagonisms can intensify, stabilize or decrease depending on the behaviour of actors, social transformations and institutional responses. Future developments will depend in particular on the ability of democracies to maintain credible electoral procedures, to preserve the autonomy of their checks and balances and to offer citizens effective opportunities for participation.

A first trajectory would correspond to a long-term but institutionally contained polarization. The parties would continue to defend highly differentiated programs and voters would retain marked political affiliations, without these oppositions leading to the systematic questioning of the legitimacy of the institutions. Alternations would remain accepted and political leaders would retain the possibility of negotiating limited agreements on certain issues. In this configuration, polarization would be a characteristic of democratic competition rather than a factor of institutional degradation.

A second trajectory would see a long-term paralysing polarisation. Partisan antagonisms would not necessarily lead to a formal questioning of democratic rules, but they would increase the costs of cooperation between political forces. The formation of majorities, the adoption of budgets and the continuity of public policies would become more difficult. The institutions would retain their legal functioning, but their ability to produce collective decisions could deteriorate. This configuration would be particularly restrictive for States faced with significant investment needs or reforms requiring continuity over several decades.

A third trajectory would correspond to polarization accompanied by institutional degradation. In this scenario, some political actors would use antagonisms to justify restrictions on future competition, to systematically contest electoral results, or to weaken the institutions responsible for controlling their actions. Polarization would no longer be just an obstacle to cooperation: it would become a resource for legitimizing behaviors that are contrary to democratic principles. Svolik’s work shows why this trajectory can be facilitated when voters prioritize their partisan loyalty over the defense of common rules^[18].

These trajectories should not be considered as three successive stages. One society can experience significant polarization without entering into a dynamic of democratic erosion. Another may see its institutional situation deteriorate even though some indicators of partisan hostility remain relatively stable. The work of International IDEA reminds us that transformations in the quality of democracy are neither uniform nor exclusively negative. Its 2026 report identifies significant setbacks, but also improvements in several national contexts, which underlines the role of institutional responses and civic mobilizations in the evolution of regimes^[19].

The 2035 horizon must therefore be considered as a framework for analysing the conditions of democratic resilience. The main challenge will not be to determine whether societies are becoming more consensual, but to know whether their institutions retain the capacity to organise intense conflicts without the actors seeking to remove the guarantees allowing their future expression.

Preserving democratic conflict while strengthening institutional capacity

Responses to polarization must be based on a fundamental principle: political pluralism is not a failure to be corrected. A democracy must allow for the expression of contradictory preferences, the organization of collective mobilizations, and the contestation of public decisions. Any policy aimed at reducing polarization by imposing ideological moderation or artificially limiting opposition would risk undermining the freedoms it claims to protect. The institutional objective must therefore be to preserve the conditions under which disagreements remain compatible with the recognition of common rules.

The first priority is the credibility of electoral procedures. Political competition is based on the possibility of losing an election without losing the right to participate in the next one. This ensures transparent procedures, competent authorities, accessible control mechanisms and legally regulated avenues of challenge. The publication of verifiable information on the organisation of elections, results and appeals helps to reduce the space available for unfounded accusations. However, it is not sufficient when some actors deliberately choose to delegitimize institutions. The responsibility of leaders in recognising results and respecting procedures therefore remains essential.

The second priority concerns the autonomy of checks and balances. Courts, supervisory authorities, independent administrations and bodies responsible for producing public data must have guarantees that allow them to carry out their missions without directly depending on immediate partisan interests. Their independence does not exempt them from criticism or evaluation. On the contrary, it requires that their functioning can be controlled according to procedures defined in advance and that disagreements on their decisions be dealt with within recognised legal frameworks. Institutional credibility depends as much on the quality of the guarantees as on their visibility among citizens.

The third priority is to strengthen the effective possibilities for political participation between elections. The OECD results show that the recognition of the usefulness of voting does not automatically translate into a feeling of being heard in public decision-making. The challenge therefore goes beyond the periodic organisation of elections and concerns the way in which institutions involve citizens in the policies that affect them. Public consultations, deliberative mechanisms and mechanisms for territorial participation can contribute to this evolution, provided that their purpose is clearly defined and that the contributions collected are explicitly answered^[20].

This is particularly important. Consultation without identifiable consequences can reinforce the perception that participation is a symbolic procedure rather than a real possibility of influence. Institutions should therefore clarify what is a matter for political decision-making, the scope for modification open to participants and the reasons why certain proposals are retained or rejected. Participation cannot replace the responsibility of elected representatives, but it can improve the quality of the information available and reduce the perceived distance between citizens and decision-makers.

The fourth priority concerns the continuity of certain strategic policies. Democracies must be able to organise alternations of government without each change of majority making it impossible to continue long-term investments. This continuity does not presuppose the existence of a permanent consensus on objectives or instruments. It can be based on limited institutional agreements, independent evaluations and programming mechanisms that make it possible to distinguish between structuring commitments and legitimately revisable orientations. Defence, infrastructure, education and research policies are areas in which this planning capacity can be of particular importance.

The fifth priority concerns the quality of the information environment. Responses must combine transparency of platforms, access to public data, protection of journalistic independence and development of verification capacities. The experimental results of Nyhan and his co-authors, however, invite us to avoid the idea that a simple algorithmic modification would be enough to reduce polarization in the long term. Political affiliations are built through social experiences, individual trajectories and mobilization strategies that go far beyond exposure to a particular content^[21].

Finally, reducing vulnerabilities related to polarization requires an improvement in the capacity for public action itself. When institutions appear incapable of dealing with collective problems in the long term, mistrust can increase the attractiveness of discourses that challenge their legitimacy. An administration that is able to produce accessible services, justify its decisions and acknowledge its mistakes helps to preserve the credibility of the political system. This dimension does not replace democratic representation, but it is an important complement to it.

The relationship between polarisation and governance must therefore be addressed in both directions: political antagonisms can weaken the capacity of institutions to act, while public action perceived as ineffective or insufficiently receptive can contribute to reinforcing antagonisms. The most relevant responses therefore consist in acting simultaneously on the quality of procedures, the capacity for representation and the effectiveness of public action.

The aim remains to preserve a fundamental distinction: the possibility of vigorously challenging a decision must remain compatible with the recognition of the legitimacy of the institutions responsible for taking and applying it.

Conclusion

Political polarization is not an anomaly specific to contemporary democracies. Representative societies have always been affected by significant economic, social, cultural and ideological oppositions. These conflicts have helped to structure party systems, to organize the representation of interests and to make major institutional transformations possible. The existence of deep disagreements is therefore not enough to characterize a democratic crisis. On the contrary, it can testify to the vitality of a political space in which citizens have the freedom to defend different conceptions of the general interest.

Contemporary transformations are more concerned with how these disagreements relate to collective identities and institutions. When party affiliations become central criteria for evaluating individuals, programmatic divergences can turn into lasting hostility between groups. Economic, cultural, or territorial controversies then tend to be interpreted through more general political opposition, while compromises become more costly because they are perceived as concessions to a fundamentally illegitimate adversary.

This evolution is not the result of a single cause or a uniform dynamic. Economic and social transformations can create tensions, but their translation into antagonisms depends on mobilization strategies, institutions and information environments. Digital platforms modify the visibility and circulation of controversies without explaining, on their own, the formation of partisan identities. International comparisons also show that highly divided societies can experience different institutional trajectories depending on the strength of their counter-powers, the rules of competition and the behaviour of leaders.

Polarization becomes particularly worrying when it affects the recognition of common institutions. A democracy is based on the possibility of competition whose results are uncertain, but whose procedures remain sufficiently recognized to allow for alternation. When citizens consider that the victory of their opponents constitutes a threat justifying the circumvention of the rules, partisan loyalty can compete with the defense of democratic principles. The institutions responsible for arbitrating conflicts then become themselves objects of confrontation, which gradually reduces their ability to be recognized beyond the groups they temporarily favor.

This transformation has a strategic dimension. A state’s ability does not depend solely on its financial, administrative, technological or military resources. It also depends on its ability to organize collective decisions, maintain long-term commitments, and mobilize society around policies whose benefits are not necessarily immediate. A long-term crippling polarization can increase the costs of negotiation, reduce the continuity of public policies, and weaken the credibility of the institutions responsible for implementing them. In societies facing major industrial, energy, and technological transitions, this difficulty can become a significant constraint on the capacity for public action.

The answer, however, cannot be to seek to erase political oppositions. A democracy in which conflicts are neutralized in the name of efficiency would lose some of the mechanisms that make it possible to control power and correct decisions. Contestation, alternation and contradiction are essential institutional resources. Their value depends precisely on the possibility of exercising them without calling into question the political existence of those who defend different positions.

Democratic resilience therefore presupposes an articulation between two requirements. The first is to preserve the freedom to confront interests, programs and values. The second is to maintain rules, checks and balances and procedures that are sufficiently credible so that this confrontation remains compatible with the collective exercise of power. These requirements are not contradictory. They define the conditions under which pluralism can produce legitimate decisions without requiring uniformity of preferences.

The evolution of polarization over the coming decades will largely depend on this institutional capacity. Democracies will have to face disagreements that are likely to persist over the distribution of resources, collective identity, technological transformations and strategic priorities. Their stability cannot therefore be based on the assumption of a spontaneous return to consensus. It will depend on their ability to organize these conflicts without the actors renouncing to recognize the guarantees that will allow them to be expressed in the future.

Strategic vulnerability arises when political opponents stop seeing themselves as legitimate competitors and begin to treat common institutions as instruments whose value depends exclusively on their victory.

Polarization then becomes more than an intensification of political debate: it transforms the conditions for the production of legitimacy and can weaken society’s ability to act collectively. Conversely, a democracy capable of maintaining the mutual recognition of actors, the credibility of its procedures and the continuity of certain policies can withstand deep divisions without losing its decision-making capacity.

The fundamental question of the twenty-first century will therefore not be how to eliminate political disagreements, but how to preserve institutions that are legitimate enough for deeply divided citizens to continue to agree to decide together on their collective future.

^[1] Reiljan, 2020, https://doi.org/10.1111/1475-6765.12351

^[2] Nyhan et al., 2023, https://doi.org/10.1038/s41586-023-06297-w

^[3] Svolik, 2019, https://doi.org/10.1353/jod.2019.0039

^[4] McCoy & Somer, 2019, https://doi.org/10.1177/0002716218818782

^[5] Reiljan, 2020, https://doi.org/10.1111/1475-6765.12351

^[6] McCoy & Somer, 2019, https://doi.org/10.1177/0002716218818782

^[7] Reiljan, 2020, https://doi.org/10.1111/1475-6765.12351

^[8] McCoy & Somer, 2019, https://doi.org/10.1177/0002716218818782

^[9] Nyhan et al., 2023, https://doi.org/10.1038/s41586-023-06297-w

^[10] V-Dem Institute, 2025, https://www.v-dem.net/documents/60/V-dem-dr__2025_lowres.pdf

^[11] Svolik, 2019, https://doi.org/10.1353/jod.2019.0039

^[12] OECD, 2026, https://doi.org/10.1787/f1cdd038-fr