Polarization, extremism, and proportional representation

How would electoral reform impact the trend towards extremist, anti-democratic politics?
A man in a helmet leans down on January 6, 2021.

Studies observe different levels of polarization and antidemocratic extremism in countries with winner-take-all systems as compared to those with proportional representation. 

Affective polarization — or dislike of, as opposed to just disagreement with, partisan opponents — intensifies in countries with winner-take-all systems and decreases with more proportional ones. Winner-take-all systems generally seem to be less successful at managing partisan conflict, especially in “deeply divided societies” such as the U.S. Indeed, research also finds that more proportional electoral systems correlate with lower levels of ethnic-based political violence in highly polarized contexts. 

Differences are driven largely by the presence and interaction of more viable parties in more proportional systems. Winner-take-all systems typically use single-member districts, while proportional systems use multi-member districts; and as a general rule, for a given assembly size, as the number of seats per district increases, so too does the number of seat-winning political parties. That is, more seats per district creates space for more parties to organize and contest those seats. 

How do more parties, then, affect polarization and extremism? Principally, by allowing for more dynamic coalition-building among them than is typically possible in two-party systems. Research finds that issue-based and identity-based polarization are lower in countries with proportional systems and multiparty coalitions. Because multiparty coalitions bring different partisans together across time, and require compromise among them, both elites and voters tend to exhibit less inter-party hostility. Whereas winner-take-all systems tend to structure political conflict as binary — pitting two dominant camps against one another — proportional ones permit a greater fluidity in politics, where, as Lee Drutman observes, “few political enemies are ever permanent.” 

In a 2014 survey of 31 democracies, the U.S. featured the strictest two-party system. The system’s rigidity is in part due to a panoply of state regulations designed to prevent new and minor parties from being electorally competitive, such as prohibitive ballot access laws and bans on fusion voting. But the number of electorally competitive parties is also a function of electoral rules, such as the number of seats per district. By fracturing the binary conflict structured by America’s rigid two-party system, and making room for the “the shifting politics of coalition formation in proportional democracies,” a more proportional system may help to rein-in spiraling polarization. 

Having more seat-winning parties may also aid efforts to combat escalating extremism. Across democracies, multiparty coalitions have been at the forefront of efforts to confront and isolate extremist movements, including strategic coalitions between left- and right-leaning parties. In the U.S., there are far fewer opportunities for competitive pushback against extremists within the two-party system. For instance, extremists within the current Republican Party are generally well-insulated from new competition, such as from challengers that might arise from a new center-right party and coalitions such as a party might form to marginalize extremists. 

Marginalizing extremism becomes significantly more difficult once extremists gain a foothold within one of only two major parties, as they are incentivized to use the major parties as a path to power absent other options. While multiparty systems tend to provide more extremist parties with legislative seats in the first instance, it is less likely that extremist movements commandeer a major party or majority coalition altogether. Instead, in multiparty democracies, political extremists unwelcome in mainstream parties tend to create their own, and secure limited seats in proportion to limited support.

Proportional representation may also strengthen “losers’ consent,” or the willingness of those who lose an election to accept their loss and legitimize a democratically elected government. This foundational tenant of stable and peaceful democracies is under threat in the U.S., where the share of candidates and officeholders denying election results has skyrocketed. (A majority of Republican candidates for the 2022 midterm elections refused to accept the legitimacy of the 2020 presidential elections.) By giving political minorities more seats at the table, proportional systems can disincentivize such extremist behavior

As Matthew Germer of R Street observes: “Proportional representation reduces the impact of losing a vote by giving losers more influence in the overall composition of their government. This directly encourages losers’ consent by diminishing the number of people who fall squarely in the ‘loser’ category and ensures that political minorities still have a voice in their government.”

Proportional representation reduces the impact of losing a vote by giving losers more influence in the overall composition of their government. This directly encourages losers’ consent by diminishing the number of people who fall squarely in the ‘loser’ category and ensures that political minorities still have a voice in their government.

Matthew Germer, R Street

A fulsome review of the potential implications of a more fluid party system are beyond the scope of this analysis, as many depend on other country-specific factors. However, creating space for additional parties — something desired by more than 70 percent of Americans — ought to figure as a major consideration (and potentially explicit goal) of electoral system reform, especially given the variety of effects relevant to issues like polarization and extremism currently straining American democracy. 

This analysis is excerpted from Towards Proportional Representation for the U.S. House, published by Unite America and Protect Democracy. Read the full report here.

About the Authors

Grant Tudor

Policy Advocate

Grant Tudor develops and advocates for a range of reforms to shore up our democratic institutions.

Beau Tremitiere


Beau Tremitiere develops and leads advocacy projects targeting political extremism and authoritarianism, including litigation challenging the constitutionality of state laws prohibiting fusion voting.

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