Is political polarization worse than it's been in the past?

Leans yesSays it is contested

Whether political polarization is worse today than in the past depends heavily on how you measure it and what era of history you are comparing it to.

According to political scientists, while the current level of polarization is not the worst in all of American history—which would be the Civil War—it is the deepest, most systemic, and most hostile polarization the country has experienced in over a century.

1. Where We Are at Modern Highs (Since the Late 19th Century)

In terms of how political parties behave and how the public views the "other side," today’s polarization is at historic highs.

•Congressional Ideological Distance: Political scientists use "DW-NOMINATE" scores to track the voting records of members of Congress over time. This data shows that the ideological distance between Democrats and Republicans is greater than at any point since the Reconstruction Era of the late 1870s.

•The Death of the Moderate: In the 1960s and 1970s, there was a massive overlap between the two parties, meaning the most conservative Democrats were more conservative than the most liberal Republicans. Today, that "overlap interval" is zero. Moderates have virtually disappeared from Capitol Hill.

•Affective Polarization (Out-Group Animosity): Perhaps the most dangerous trend is not just that Americans disagree on policies (ideological polarization), but that they increasingly dislike and distrust each other (affective polarization).

•Immorality: Pew Research Center polling shows that in 2022, 72% of Republicans and 63% of Democrats viewed the opposing party as "more immoral" than other Americans—a massive spike from just 2016 (when it was 47% and 35%, respectively).

•Marriage: In 1960, only 4% to 5% of Americans said they would be displeased if their child married someone of the opposing political party. By the 2010s, that number had surged to roughly one-third of Democrats and half of Republicans.

2. When Was Polarization Worse?

If we look at the entire arc of American history, we have seen periods of even greater existential friction, though they manifested differently:

•The Civil War Era (1850s–1860s): This remains the absolute peak of American polarization. The country physically fractured, leading to a war that cost hundreds of thousands of lives.

•The Late 1960s and Early 1970s: During the Civil Rights movement, the Vietnam War, and the Watergate scandal, the U.S. was plagued by widespread social upheaval, riots in major cities, bombings by radical domestic groups, and high-profile political assassinations (including Martin Luther King Jr. and Robert F. Kennedy). Interestingly, while the public was highly divided, the political parties in Congress remained cooperative on many legislative fronts. Today, we have the opposite: lower levels of widespread physical violence, but a complete freeze in government cooperation.

3. Why Modern Polarization Feels Different (and Uniquely Dangerous)

Several structural shifts make today’s polarization particularly difficult to resolve compared to past eras:

•The "Mega-Identity" Sorting: In the mid-20th century, your political party didn't tell someone everything about you. You could be a conservative Southern Democrat or a liberal Northeastern Republican. Today, geographic, racial, cultural, and religious identities have cleanly sorted into the two major parties. Political affiliation has become a "mega-identity," meaning a political disagreement is now processed as a personal threat to one's culture and lifestyle.

•The post-2008 Digital Leap: A study from the University of Cambridge tracked U.S. social and political divisions over four decades, finding that polarization largely flatlined in the 1990s and early 2000s, but surged by 64% from 2008 onward. This turning point aligned with the rise of smartphones, algorithmic social media, and the financial crisis. Modern media business models thrive on outrage, systematically exposing voters to the most extreme voices of the opposing party.

•The U.S. is an International Outlier: A landmark study from Brown University found that while some other Western democracies have seen modest increases in polarization, the United States is polarizing much faster than peer nations (like Canada, the UK, Germany, and Australia). The U.S. is uniquely susceptible due to its rigid two-party system, which forces voters into an "us versus them" binary, unlike multi-party parliamentary systems.

Summary

If you are comparing today to the Civil War, polarization is not at its historic worst. But if you are comparing today to the last 100 years, we are living through an era of unprecedented ideological separation, historic levels of mutual animosity, and a complete lack of political crossover—all supercharged by modern technology and geographic sorting.

Citations (10)

1usc.eduAcademic
usc.edu
Backs: “According to political scientists, while the current level of polarization is not the worst in all of American history—which would be the Civil War—it is the deepest, most systemic, and most hostile polarization the country has experienced in over a century.”
attribution, other, points to yes. Claim: Political scientists say current polarization is the deepest and most hostile in over a century, though not worse than the Civil War era.
2democracyproject.orgNonprofits and think tanks
democracyproject.org
Backs: “According to political scientists, while the current level of polarization is not the worst in all of American history—which would be the Civil War—it is the deepest, most systemic, and most hostile polarization the country has experienced in over a century.”
attribution, other, points to yes. Claim: Political scientists say current polarization is the deepest and most hostile in over a century, though not worse than the Civil War era.
3pewresearch.orgNonprofits and think tanks
pewresearch.org
Backs: “Congressional Ideological Distance: Political scientists use "DW-NOMINATE" scores to track the voting records of members of Congress over time. This data shows that the ideological distance between Democrats and Republicans is greater than at any point since the Reconstruction Era of the late 1870s.”
evidence, article, points to yes. Claim: DW-NOMINATE scores show the ideological distance between congressional parties is greater than at any point since Reconstruction.
4wikipedia.orgEncyclopedias and referencequality 0.83
wikipedia.org
Backs: “Affective Polarization (Out-Group Animosity): Perhaps the most dangerous trend is not just that Americans disagree on policies (ideological polarization), but that they increasingly dislike and distrust each other (affective polarization). Immorality: Pew Research Center polling shows that in 2022, 72% of Republicans…”
background, reference entry, points to yes. Claim: Americans increasingly dislike and distrust the other party, defined as affective polarization, rather than just disagreeing on policy.
5syr.eduAcademic
syr.edu
Backs: “Immorality: Pew Research Center polling shows that in 2022, 72% of Republicans and 63% of Democrats viewed the opposing party as "more immoral" than other Americans—a massive spike from just 2016 (when it was 47% and 35%, respectively). Marriage: In 1960, only 4% to 5% of Americans said they would be displeased if…”
statistic, article, points to yes. Claim: In 2022, 72% of Republicans and 63% of Democrats viewed the other party as more immoral, up from 47% and 35% in 2016.
6wikipedia.orgEncyclopedias and referencequality 0.83
wikipedia.org
Backs: “Marriage: In 1960, only 4% to 5% of Americans said they would be displeased if their child married someone of the opposing political party. By the 2010s, that number had surged to roughly one-third of Democrats and half of Republicans.”
statistic, reference entry, points to yes. Claim: In 1960 only 4-5% would be displeased by a child marrying across party lines; this rose to a third of Democrats and half of Republicans.
7reddit.comForums and Q&A
reddit.com
Backs: “The country physically fractured, leading to a war that cost hundreds of thousands of lives. The Late 1960s and Early 1970s: During the Civil Rights movement, the Vietnam War, and the Watergate scandal, the U.S.”
evidence, other, points to no. Claim: The Civil War era physically fractured the country and cost hundreds of thousands of lives, a peak of polarization.
8brown.eduAcademic
brown.edu
Backs: “The "Mega-Identity" Sorting: In the mid-20th century, your political party didn't tell someone everything about you. You could be a conservative Southern Democrat or a liberal Northeastern Republican.”
evidence, article, points to yes. Claim: Party identity has become a mega-identity, with geography, race, culture and religion sorted into the two parties, unlike the mid-20th century.
9cam.ac.ukAcademic
cam.ac.uk
Backs: “The post-2008 Digital Leap: A study from the University of Cambridge tracked U.S. social and political divisions over four decades, finding that polarization largely flatlined in the 1990s and early 2000s, but surged by 64% from 2008 onward. This turning point aligned with the rise of smartphones, algorithmic social…”
statistic, article, points to yes. Claim: A Cambridge study found polarization flat in the 1990s-2000s but surging 64% from 2008 onward.
10facinghistory.orgNonprofits and think tanks
facinghistory.org
Backs: “is uniquely susceptible due to its rigid two-party system, which forces voters into an "us versus them" binary, unlike multi-party parliamentary systems. Summary”
evidence, article, points to yes. Claim: The US two-party system makes it uniquely susceptible to us-versus-them polarization compared with multi-party parliamentary systems.