The rise of political polarization in the United States has pushed analysts to ask a fundamental question: what long-term effects will polarized politics have on the United States’ democracy?1 Existing evidence provides ample reason for concern. At the elite level, deep political divides in Washington have crippled efforts at legislative compromise, eroded institutional and behavioral norms, and incentivized politicians to pursue their aims outside of gridlocked institutions, including through the courts. Yet these divides extend far beyond the corridors of power, as polarization at the mass level is pushing Americans across the country to divide themselves into distinct and mutually exclusive political camps. The rise of an “us versus them” mindset and political identity in American sociopolitical life is evident in everything from the rise of highly partisan media to the decline in Americans’ willingness to marry someone from the opposing political party.2 Even more concerningly, these dynamics are contributing directly to a steep rise in political violence.3 Polarization has already brought on serious problems—what more lies ahead? Are insights on this critical question available from the experience of other polarized democracies?

Many other democracies around the world have grappled or are grappling with the difficulties posed by the onset of pernicious polarization, which McCoy and Somer have defined elsewhere as the division of society into mutually distrustful political camps in which political identity becomes a social identity.4 The experiences of these other countries can provide useful insights into the United States’ own struggles—and may help to predict what may be to come. Comparative studies have already shown that pernicious polarization is directly linked with democratic erosion and that the United States is far from the only democracy to confront severe polarization.5 Yet broader context for understanding how democracies fare when facing pernicious polarization is lacking.

Jennifer McCoy
Jennifer McCoy is a nonresident scholar in the Democracy, Conflict, and Governance Program, where she focuses on political polarization and democratic resilience in the U.S. and around the world.
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To rectify this gap, we used the Varieties of Democracy (V-Dem) data set to take a close look at episodes of pernicious polarization around the world since 1950 and trace their relationships with levels of democracy.6 The findings are not encouraging. Severe polarization correlates with serious democratic decline: of the fifty-two instances where democracies reached pernicious levels of polarization, twenty-six—fully half of the cases—experienced a downgrading of their democratic rating.7 Only sixteen episodes were able to reduce polarization to below-pernicious levels, and the decline in polarization was only sustained in nine of those cases. Quite strikingly, the United States is the only advanced Western democracy to have faced such intense polarization for such an extended period. The United States is in uncharted and very dangerous territory.

Political Outcomes of Pernicious Polarization

To situate the United States’ experience within the broader universe of polarized democracies, we compiled a comprehensive list of episodes since 1950 when a democracy reached pernicious levels of polarization for at least two years.8 We then compared the trajectories of their democratic ratings with their levels of political polarization.9

Four basic outcomes were possible from this comparison, as reflected in table 1:

  • The country manages to depolarize and keep its democracy intact.
  • The country manages to depolarize but suffers democratically.
  • The country’s democracy is able to live with the chronically high levels of polarization without undergoing any democratic downgrading (to date).
  • The country experiences pernicious polarization and a downgrading of its democracy score.
Table 1: Outcomes of Episodes of Pernicious Polarization
    Stable Downgraded
Remains Pernicious 10 26


The data show that it is possible for democracies to depolarize. In these cases, listed in table 2, the public and the political elite were able to find ways to reduce the tensions that have divided them. The diversity of these cases shows that there are many ways of doing this: in some instances, divides over the future of the country were able to be resolved through democratic processes, while the rule of law checked polarizing leaders who were concentrating power elsewhere. For example, Brazil’s newly restored democracy allowed for the successful impeachment and removal of its president following a corruption scandal in 1992, and a decade later managed the smooth transition to a government led for the first time by the leftist Workers Party. In Colombia between 2009 and 2010, an independent Constitutional Court restrained a president attempting to push through a constitutional amendment to allow him to run for a third term.

Benjamin Press
Benjamin Press is a nonresident research analyst in the Democracy, Conflict, and Governance Program.

Other cases benefited from international intervention, such as in Timor-Leste in 2006, when the threat of a military rebellion immediately polarized the country’s politics and only depolarized after foreign military forces helped stabilize the country and the prime minister resigned. Finally, political agreements between elites may depolarize a country’s politics. In Bolivia, for example, highly charged disputes in 2008 over autonomy for the country’s southern regions were resolved through negotiations and a political settlement that provided for a constitutional referendum.

These cases illustrate that depolarization—though very difficult—is possible. However, it is often quite fragile; as table 2 shows, a significant number of instances later repolarized to pernicious levels. The progress toward depolarization in seven of sixteen episodes was later undone, underscoring that the threat of pernicious polarization never fully disappears.

Table 2: Cases of Depolarization From Pernicious Levels
  1. Bolivia, 2003–2005 [repolarizes in 2007]
  2. Bolivia, 2007–2012 [repolarizes in 2016]
  3. Brazil, 1989–1993 [repolarizes in 2012]
  4. Colombia, 2009–2011 [repolarizes in 2014]
  5. Cyprus, 1974–1989
  6. El Salvador, 1999–2010
  7. Georgia, 2007–2015 [repolarizes in 2017]
  8. Guyana, 1998–2020
  9. Indonesia, 2000–2020
  10. Malta, 1963–1990 [repolarizes in 2014]
  11. Mauritius, 2019–2020
  12. Nepal, 2014–2020
  13. Senegal, 1988–1991 [repolarizes in 1993]
  14. Senegal, 1993–1995
  15. Suriname, 1992–1997
  16. Timor-Leste, 2006–2008
Note: The start of each episode represents the first year in which the country attained both pernicious levels of polarization (3.0 on V-Dem’s political polarization metric) and a democratic Regimes of the World score (either liberal or electoral democracy). The end year of each episode denotes the year in which V-Dem’s polarization metric declines below pernicious levels. The year in which a country repolarizes is the year in which the polarization score returned to pernicious levels.

Persistent Polarization Without Democratic Degradation

This survey also yielded a group (see table 3) of countries that have experienced chronically pernicious levels of polarization for some time without undergoing democratic downgrading. Some countries, like Bosnia and Ecuador, have managed to juggle pernicious polarization and at least somewhat functional democracy for many years. While it is beyond the scope of this article to speculate as to why this might be, institutional factors like Bosnia’s ethnoreligious power-sharing agreement backed by international institutions and neighboring countries may play a key role. However, for other countries, like Brazil, Mexico, and the United States, the onset of pernicious polarization is a much more recent phenomenon, and it is far from clear that their institutions will successfully manage the pressures of pernicious polarization. Indeed, a more sensitive metric—V-Dem’s Liberal Democracy Index—shows that many members of this group, including Brazil, Colombia, Georgia, Mexico, and the United States, have seen their democratic health suffer since becoming perniciously polarized, albeit not to the point where their score on the Regimes of the World (RoW) index was downgraded. Especially for more recently polarized countries, their membership on this list may be more transitory as they either find a way to depolarize or their democracies degrade. All of the countries on this list, with the exception of the United States, are electoral democracies that lack the full protections of a liberal democracy.

Table 3: Cases of Chronic Pernicious Polarization and Sustained Democracy
  • Argentina, 2013–present
  • Bosnia and Herzegovina, 1999–present
  • Brazil, 2013–present
  • Colombia, 2014–present
  • Ecuador, 2007–present
  • Georgia, 2017–present
  • Malta, 2014–present
  • Mexico, 2019–present
  • North Macedonia, 2017–present
  • United States, 2015–present
Note: The beginning year of the episode represents the first year the country became perniciously polarized (defined as above 3.0 on V-Dem’s political polarization metric).

Polarization and Democratic Decline

The most common outcome of episodes where democracies reached pernicious levels of polarization was some form of major democratic decline. In total, twenty-six out of the fifty-two observed episodes (or 50 percent of cases) saw their country’s RoW score downgraded, with the vast majority of those—twenty-three of twenty-six—descending into some form of authoritarianism. The other three cases underwent backsliding within democracy, falling from liberal democracy status to be reclassified as an electoral democracy. The full list of such cases is shown in table 4.

Table 4: Outcomes of Episodes of Pernicious Polarization
Backsliding Within Democracy [From Liberal Democracy to Electoral Democracy] Erosion From Democracy to Electoral Autocracy [From Liberal or Electoral Democracy to Electoral Autocracy] Democratic Collapse [From Liberal or Electoral Democracy to Closed Autocracy]
  • Mauritius, 1968–2019
  • Bangladesh, 1992–2002
  • Argentina, 1964–1966
  • Poland, 2011–2016
  • Comoros, 2010–2015
  • Argentina, 1974–1976
  • Slovenia, 2018–2020
  • Dominican Republic, 1982–1990
  • Chile, 1970–1973
    • Hungary, 2010–2018
    • Fiji, 1993–2000
    • India, 2014–2019
    • Fiji, 2002–2006
    • Indonesia, 1956–1958
    • Malta, 1950–1957
    • Kosovo, 2002–2005
    • Thailand, 2004–2006
    • Lebanon, 2010–2018
    • Turkey, 1966–1980
    • Maldives, 2009–2013
    • Uruguay, 1966–1973
    • Montenegro, 2004–2006
    • Nepal, 2010–2012
    • North Macedonia, 2008–2012
    • Suriname, 1988–1991
    • Turkey, 2002–2013
    Note: Episode years are determined as follows: the first year of the episode is the year that the country first reached pernicious levels of polarization, and the end year is the year in which the country’s RoW score was downgraded.

    This list illustrates clearly that extraordinary levels of polarization have been an important feature of the ongoing wave of democratic decline. Indeed, fourteen of the twenty-six countries in table 4 saw their democracies downgraded since 2005, the year widely observed to have been the beginning of a new global wave of autocratization.10 Some of the world’s most prominent backsliders, including Hungary, India, Poland, and Turkey, register on the list.

    This wide assortment of countries illustrates how polarization can contribute to democratic downgrading in multiple ways. In some cases, as in Bangladesh in 2002 or Thailand in 2006, polarization—and government dysfunction—became so intense that security forces stepped in and attempted to realign the country’s politics. In other cases, like Turkey and Poland, leaders relied on explicitly polarizing populist strategies to gain and retain power, sowing division to energize their supporters while claiming that it is necessary to curtail democracy in order to overcome opponents’ resistance and enact their agenda.

    American Exceptionalism

    Another troubling realization stands out: the United States is quite alone among the ranks of perniciously polarized democracies in terms of its wealth and democratic experience. Of the episodes since 1950 where democracies polarized, all of those aside from the United States involved less wealthy, less long-standing democracies, many of which had democratized quite recently. None of the wealthy, consolidated democracies of East Asia, Oceania, or Western Europe, for example, have faced similar levels of polarization for such an extended period, as figure 1 shows.11

    Only two other episodes come close. First, France briefly reached pernicious levels of polarization during its 1968 political crisis, when student protests and union strikes pushed France’s government to the brink of collapse. However, the unrest faded within a few months and the temperature of politics quickly returned to a more normal level with the signing of the Grenelle Accords and the holding of legislative elections in June 1968. The other episode was in Italy between 1971 and 1978, when levels of polarization were just shy of pernicious as the country faced a surge of violence from far-right and far-left terrorist groups. Italy eventually depolarized as the major political parties agreed to jointly address the violence, law enforcement cracked down on terrorism, and public support for extremist movements faded. Italy has been repolarizing in recent years, however, and reached pernicious levels in 2020. Yet neither Italy nor France reached levels of political polarization as high as the United States’ current levels for as long a period. There are no peer analogues for the United States’ current political divisions—and the track record of all democracies does not provide much consolation.

    This status as an outlier could stem from a number of features that make the United States both especially susceptible to polarization and especially impervious to efforts to reduce it. One such feature is the durability of identity politics in a racially and ethnically diverse democracy. The United States is not the only such democracy—Brazil and India are large multiracial and multicultural democracies also suffering pernicious polarization, while Canada and Australia are increasingly multicultural but without such levels of polarization. Yet the United States is perhaps alone in experiencing a demographic shift that poses a threat to the white population that has historically been the dominant group in all arenas of power, allowing political leaders to exploit insecurities surrounding this loss of status.

    Second, institutional characteristics likely contribute to the sustained severe polarization in the United States. Binary choice is deeply embedded in the U.S. electoral system, creating a rigid two-party system that facilitates binary divisions of society. For example, only five of twenty-six wealthy consolidated democracies elect representatives to their national legislatures in single-member districts.12 Like the United States, these countries tend to have two-party dominant systems; however, most have also seen new parties rise over the last two decades, a development that has not been mirrored in the United States. 

    Another institutional factor is the unique combination of a majoritarian electoral system with strong minoritarian institutions in the United States. The Senate is highly disproportionate in its representation, with two senators per state regardless of population, from Wyoming’s 580,000 to California’s 39,500,000 persons. The practices of the Senate also give individual senators unusual authority to single-handedly hold up presidential nominations or debate on legislation, while the filibuster rule enables the minority party to block consideration of legislation that would have a majority vote in favor. These contribute to government gridlock and fuel public disapproval of Congress. Finally, the disproportionality of Senate representation translates to disproportionality in the Electoral College—whose indirect election of the president is again exceptional among presidential democracies.

    A third factor contributing to the seemingly entrenched political polarization in the United States is the three-decade-old trend of partisan sorting, in which the two parties reinforce urban-rural, religious-secular, and racial-ethnic cleavages rather than promote cross-cutting cleavages. With partisanship now increasingly tied to other kinds of social identity, affective polarization is on the rise, with voters perceiving the opposing party in negative terms and as a growing threat to the nation.13 Voters also tend to follow cues from party leaders about policy positions and there is greater homogeneity within parties, impeding the kind of cross-party coalitions common in the past. With such perceptions of threat, voters are more willing to tolerate or even embrace antidemocratic actions by their leaders.

    Partisan sorting and rising polarization create a pernicious logic of zero-sum politics that incentivizes behavior undermining democratic institutions and norms. The final year of Donald Trump’s presidency saw the president and his party fuel a false narrative to discredit the electoral process, attempt to overturn the presidential election, and refuse to disavow political violence. All of these factors impede attempts to overcome pernicious polarization and portend an ominous future for American democracy.


    Placing the United States’ struggles with pernicious polarization in a broader context yields a deeply troubling picture. At least since 1950, no other established democracy has become this polarized for this long. Within the broader pool of perniciously polarized democracies, the comparisons become even less encouraging—a plurality have descended into authoritarianism, and even those that depolarize face significant risks of repolarizing in the future. This reinforces a key theme emerging in the growing field of literature on how polarization plays out in different contexts: pernicious polarization is a uniquely corrosive and dangerous force in democracies. 

    Yet all is not lost. Systemic interventions can help reduce polarization before polarization imperils democracy. Whether through institutional reform, voter education, or sounding the alarm about the dangers to democracy, policymakers, activists, and civic leaders should urgently prioritize systemic efforts that will change the incentives undergirding the dangerous binary logic of pernicious polarization. Such reforms should aim to lower the high stakes of elections and give voters more voice and more choice.14

    Lessons from abroad give us some hints: reforms such as shifting to a proportional representation system (as New Zealand did in the 1990s) and/or using ranked choice voting in multimember districts (such as in Ireland) could break up America’s rigid binary logic, give voters more choice, and allow for coalition-building to ease the gridlock. Political parties and cultural influencers need to clearly distance themselves from individuals and groups employing political violence, exclusionary nationalist appeals, or antidemocratic measures, as the Italian parties did to end a decade of violence in the 1970s. Elected leaders should listen to legitimate grievances and pursue policies to benefit the whole, not just one party or a small elite. Reducing the threat of pernicious polarization to democracy requires deliberate, urgent action. Or, as this research suggests, American democracy itself may cease to be.


    1 This article is part of a larger project from the Carnegie Endowment for International Peace on comparative depolarization, led by Jennifer McCoy and Murat Somer.

    2 Wendy Wang, “Marriages Between Democrats and Republicans Are Extremely Rare,” Institute for Family Studies, November 3, 2020,

    3 Rachel Kleinfeld, “The Rise of Political Violence in the United States,” Journal of Democracy 32, no. 4 (October 2021): 160–76.

    4 Jennifer McCoy, Tahmina Rahman, and Murat Somer, “Polarization and the Global Crisis of Democracy: Common Patterns, Dynamics, and Pernicious Consequences for Democratic Polities,” American Behavioral Scientist 62, no. 1 (January 1, 2018): 16–42.

    5 Jennifer McCoy and Murat Somer, eds., “Special Issue on Polarized Polities: A Global Threat to Democracy,” Annals of the American Academy of Political and Social Science 681, no. 1 (January 2019); Thomas Carothers and Andrew O’Donahue, Democracies Divided: The Global Challenge of Political Polarization (Washington: Brookings Institution Press, 2019); and Murat Somer, Jennifer McCoy, and Russell Luke, “Pernicious Polarization, Autocratization and Opposition Strategies,” Democratization 28, no. 5 (2021): 929–948. 

    6 Varieties of Democracy (V-Dem) index, version 11.1, March 2021, accessed at

    7 We do not make a causal inference here that pernicious polarization causes democratic deterioration, but our prior research does show a strong correlation even lagged for one to five years. See Somer, McCoy, and Luke, “Pernicious Polarization, Autocratization and Opposition Strategies.”

    8 We identified democracies as those countries that met the definition of either “liberal democracy” or “electoral democracy” on V-Dem’s Regimes of the World measure. On this measure, a score of 0 signifies that the country is rated as a closed autocracy (defined by V-Dem as having “No multiparty elections for the chief executive or the legislature”); a score of 1 signifies an electoral autocracy (“Multiparty elections for the chief executive and the legislature, but failing to achieve that elections are free and fair”); 2 signifies an electoral democracy (“Free and fair multiparty elections but deficits in either access to justice, or transparent law enforcement, or liberal principles of respect for personal liberties, rule of law, and judicial as well as legislative constraints on the executive”); and a 3 corresponds to a liberal democracy (“Free and fair multiparty elections and access to justice, transparent law enforcement and the liberal principles of respect for personal liberties, rule of law, and judicial as well as legislative constraints on the executive satisfied.”). For more on the Regimes of the World metric, see, page 283.

    9 We defined pernicious levels of political polarization as at least a 3.0 out of 4.0 on V-Dem’s Political Polarization metric. This measure asks country experts to rate the degree to which society is polarized into antagonistic political camps, especially the extent to which political differences affect social relationships beyond political discussions. Societies are highly polarized if supporters of opposing political camps are reluctant to engage in friendly interactions, for example, in family functions, civic associations, their free time activities, and workplaces. The score ranges from 0 (low degree of polarization) to 4 (highly polarized). Under the two-year minimum condition, we removed cases like Venezuela in 2002, which, though perniciously polarized, was downgraded to an electoral autocracy in 2003 and thereby failed the condition of being both a democracy and perniciously polarized for at least two years. For more on the political polarization metric, see, page 224. 

    10 Sarah Repucci and Amy Slipowitz, “Freedom in the World 2021: Democracy Under Siege,” Freedom House, February 2021,

    11 Southern Europe’s pernicious levels of polarization until the mid-1970s reflected dictatorships in Greece, Portugal, and Spain until third-wave democratic transitions, as well as the decade of violence in Italy in the 1970s.

    12 Only three established democracies use exclusively first-past-the-post plurality voting to choose their legislators: Canada, the United Kingdom, and the United States. France adds a second round (run-off election) in its single-member district system, and Australia adds the alternative vote, or ranked choice voting, which acts as an instant runoff in its single-member-district system; for more, see “Electoral System Design Database,” International Institute for Democracy and Electoral Assistance, accessed January 10, 2022,

    13 Levi Boxell, Matthew Gentzkow, and Jesse Shapiro, “Cross-Country Trends in Affective Polarization,” National Bureau of Economic Research, January 2020.

    14 Ezra Klein, Why We’re Polarized (New York: Avid Reader Press / Simon & Schuster, 2020); Lee Drutman, Breaking the Two-Party Doom Loop: The Case for Multiparty Democracy in America (New York: Oxford University Press, 2020); and American Academy of Arts and Sciences, Our Common Purpose: Reinventing American Democracy for the 21st Century (Cambridge, MA: American Academy of Arts and Sciences, 2020).