Political polarization in the United States
is a prominent component of politics in the United States. Scholars distinguish between ideological polarization and affective polarization, both of which are apparent in the United States. In the late 20th and early 21st century, the U.S. has experienced a greater surge in ideological polarization and affective polarization than comparable democracies.
Differences in political ideals and policy goals are indicative of a healthy democracy. Scholarly questions consider changes in the magnitude of political polarization over time, the extent to which polarization is a feature of American politics and society, and whether there has been a shift away from focusing on triumphs to dominating the perceived abhorrent supporters of the opposing party.
Polarization among U.S. legislators is asymmetric, as it has primarily been driven by a rightward shift among Republicans in Congress. Polarization has increased since the 1970s, with rapid increases in polarization during the 2000s onwards. According to the Pew Research Center, members of both parties who have unfavorable opinions of the opposing party have doubled since 1994, while those who have very unfavorable opinions of the opposing party are at record highs as of 2022.
Definition and conceptualization
The Pew Research Center defines political polarization in the United States as "the vast and growing gap between liberals and conservatives, Republicans and Democrats". According to psychology professors Gordon Heltzel and Kristin Laurin, political polarization occurs when "subsets of a population adopt increasingly dissimilar attitudes toward parties and party members, as well as ideologies and policies " Polarization has been defined as both a process and a state of being. A defining aspect of polarization, though not its only facet, is a bimodal distribution around conflicting points of view or philosophies. In general, defining a threshold at which an issue is "polarized" is imprecise; detecting the trend of polarization, however, is more straightforward.The relationship between ideological and affective polarization is complicated and contested but, generally speaking, scholars recognize an increase in both ideological and affective polarization in the United States over time. Some research suggests that affective polarization is growing more rapidly than ideological polarization and perhaps even driving it. Political scientists debate the relationship between elite-driven polarization and mass polarization. Morris Fiorina argues that the American public is not as polarized as is often assumed, suggesting that elite polarization is wrongly imputed to the general public. Conversely, Alan Abramowitz argues that mass polarization is actually imposing polarization upon elites through the electoral process.
Affective polarization is closely related to political tribalism and "us-them" thinking. There is mounting psychological evidence that humans are hardwired to display loyalty towards in-groups and hostility and distrust towards out-groups, however they are defined. One way to describe this is to say that humans evolved to be partial empathizers, ready to empathize with those from whom they can expect reciprocity, while being incredibly skeptical towards outsiders. Recent research has shown that the interplay between out-group hostility and in-group empathy can be the driver of ideological polarization. Many of our cognitive biases and failures of reason can be traced directly back to our apparent need to defend our group against threats, even when those threats consist mainly of ideas and words. Motivated reasoning and confirmation bias help to explain the cognitive blindspots that lead us to dismiss or discredit challenging information while granting unwarranted credence to information that supports our pre-existing views.
For example, in one study, subjects were asked to evaluate "neutral" quantitative data regarding the efficacy of skin cream. In this treatment, subjects' performance was determined simply by their numeracy, that is, their mathematical skill level. In a second treatment, subjects were presented with data concerning the efficacy of gun control laws. Partisans performed much more poorly when asked to evaluate data that challenged their pre-existing views about gun control laws. High mathematical skill levels did not prevent this. Those who had the strongest mathematical skills were best able to rationalize a false interpretation of the data that conformed with their pre-existing views.
Similarly, Americans' views on gun control seem to stem almost entirely from their cultural worldview and how they position themselves in that cultural schema. Statistics do not persuade them to change their minds. Cognitive scientists Mercier and Sperber argue that human reason did not evolve in order to produce logical arguments, but rather to finesse social relationships. Within this view, the evolutionary purpose of reason is not truth, but persuasion and collaboration. These studies suggest that our social and partisan identities, often discussed in the context of identity politics, affect the ways in which we engage information, and may sometimes drive political polarization.
Although most studies have focussed on survey data to quantify affective polarization, social media and social network based approaches have recently been proposed to estimate the affective polarization.
History
Antebellum period
Starting in the early 1830s, the country became progressively more polarized over the issue of slavery: whether it was a great wrong, a sin, or a necessary evil or even a positive good. Neither the Missouri Compromise nor the Compromise of 1850 succeeding in dealing adequately with the problem. The pro-slavery Southern states, thanks to the Three-fifths Compromise, dominated the Federal government. Congress passed repeated gag rules preventing the issue from even being discussed.Gilded Age
The Gilded Age of the late 19th century is considered to be one of the most politically polarized periods in American history, with open political violence and highly polarized political discourse. A key event during this era was the election of 1896, which some scholars say led to an era of one-party rule, created "safe seats" for elected officials to build careers as politicians, increased party homogeneity, and increased party polarization. Political polarization was overall heightened, with Republicans strengthening their hold on industrial areas, and Democrats losing ground in the North and upper Midwest.1950s and 1960s
The 1950s and 1960s were marked by high levels of political bipartisanship, the results of a post-World War II "consensus" in American politics, as well as ideological diversity within each of the two major parties.1990–present
In the 1990s, House Speaker Newt Gingrich's use of "asymmetric constitutional hardball" led to increasing polarization in American politics driven primarily by the Republican Party. Media and political figures began espousing the narrative of polarization in the early 1990s, with a notable example being Pat Buchanan's speech at the 1992 Republican National Convention. In the speech, he declared a culture war for the future of the country.In 1994, the Democratic Party lost control of the House of Representatives for the first time in forty years. Congress went Republican for the first time since 1952. The narrative of political polarization became a recurring theme in the elections of 2000 and 2004. After President George W. Bush barely won reelection in 2004, English historian Simon Schama noted that the US had not been so polarized since the American Civil War, and that a more apt name might be the Divided States of America.
From 1994 to 2014, the share of Americans who expressed either "consistently liberal" or "consistently conservative" opinions doubled from 10% to 21%. In 1994, the average Republican was more conservative than 70% of Democrats, compared to more conservative than 94% of Democrats in 2014. The average Democrat went from more liberal than 64% of Republicans to more liberal than 92% of Republicans during the same era. In contrast, families are becoming more politically homogenous. As of 2018, 80% of marriages had spousal alignment on party affiliation. Parent-child agreement was 75%. Both of these represent significant increases from family homogeneity in the 1960s. A 2022 study found that there had been a substantial increase since 1980 in political polarization among adolescents, driven by parental influence.
A Brown University study released in 2020 found that the U.S. was polarizing faster compared to other democratic countries such as Canada, the United Kingdom, Germany, and Australia. According to Stony Brook University political scientists Yanna Krupnikov and John Barry Ryan, polarization in American politics is primarily a phenomenon among Americans who are deeply involved in politics and very expressive about their political views. Americans who are not as involved in politics are not as polarized.
Other research suggests that Americans are less polarized than they think, and that there is "significant ideological overlap and agreement on policies." Ideological polarization is felt most strongly among those who are the most politically engaged, such as progressive activists and extreme conservatives. Although Americans are less ideologically polarized than they believe, they are very emotionally polarized. In other words, "they do not like members of the other party."
According to Gallup, in 2025 the percentage of Americans self-identifying as politically moderate reached a record low of 34%. Among Republicans, 77% self-identified as conservative, 18% as moderate, and 4% as liberal. Among Democrats, 55% self-identified as liberal, 34% as moderate, and 9% as conservative. In 2025, The Wall Street Journal described the American political system as having "a total breakdown in trust" between the two parties and among the general public.