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

When evaluating whether political polarization is worse than it has been in the past, political scientists and historians generally offer a nuanced answer: No, it is not the worst it has ever been in American history (which would be the Civil War), but yes, by almost every modern metric, it is worse than it has been in over a century.

To understand how today’s political environment compares to the past, it helps to look at how polarization is measured, the historical context, and the unique characteristics of our modern divide.

1. How Polarization is Measured

Political scientists divide polarization into three main categories:

2. The Historical Comparison

The Mid-19th Century: The Ultimate Peak (Civil War)

The absolute peak of political polarization in the United States was the Antebellum period and the Civil War (1861–1865). During this era, polarization was so extreme that it resulted in the physical tearing apart of the nation, the deaths of hundreds of thousands of Americans, and literal physical violence on the floor of Congress (such as the 1856 beating of Senator Charles Sumner with a cane). By this extreme standard, today’s divisions, while intense, have not reached the point of armed, state-on-state conflict.

The Gilded Age & Reconstruction (Late 19th Century)

Using statistical models like NOMINATE scores—which analyze congressional roll-call voting patterns—political scientists can track legislative polarization over two centuries. These metrics reveal that the ideological gap between Democrats and Republicans in Congress today is wider than at any point since the Reconstruction Era of the late 1870s. For over 140 years, Congress has not been this divided or gridlocked.

The Mid-20th Century: The Bipartisan "Aberration"

For many Americans, the standard of "normal" politics is the mid-20th century (the 1940s through the 1970s). During this era, polarization was unusually low. Because the parties were not yet "sorted," there was massive ideological overlap. Southern Democrats were highly conservative, while many Northeastern Republicans were highly liberal. This forced cross-party coalition building and made bipartisanship a daily reality.

Historians argue that this highly cooperative era was actually the historical anomaly, driven by the shared national trauma of World War II and the Cold War.

3. What Makes Today’s Polarization Worse (and Unique)

While the U.S. has experienced deep policy disagreements before, today’s polarization has several unique, historically alarming features:

Record-High Affective Polarization

The most significant change in recent decades is not necessarily what we disagree on, but how we feel about each other. According to the Pew Research Center, the share of Democrats and Republicans who view the opposing party as not just politically incorrect, but "immoral," "dishonest," and "a threat to the nation’s well-being" has more than doubled over the last few decades.

Deep "Hyper-Sorting"

In the past, a person’s political identity was just one of many identities. Today, political parties have become "mega-identities." If you know someone’s stance on a single issue, or even just their geographic location (urban vs. rural) or educational background, you can predict their political party with high accuracy. This sorting removes the cross-cutting social ties (like attending the same church or civic clubs) that used to keep partisan animosity in check.

The United States is an Outlier

Research co-authored by economists and political scientists at Brown and Stanford universities found that while political polarization is rising in several democracies, the United States is polarizing much faster than other wealthy nations (such as Canada, the UK, Germany, or Sweden). The U.S. media model, institutional design (like party primaries and gerrymandering), and historical racial divisions have made it uniquely susceptible to rapid polarization.

Recent Ideological Shifts

Sociological research also tracks how the ideological gap has widened. A study from the University of Cambridge tracking American political opinions from 1988 to 2024 found that polarization escalated dramatically after 2008 (accelerating after the financial crisis and the election of Barack Obama).

Interestingly, the study noted that a large portion of this widening gap has been driven by asymmetric cultural shifts: left-leaning Americans became 31.5% more socially progressive over those four decades, while right-leaning Americans' core conservative views remained relatively stable. This rapid progressive shift left many conservatives feeling alienated, which political scientists suggest has fueled a rise in out-group animosity and cultural defense on the right.

Conclusion

Is political polarization worse than it has been in the past?

If the comparison is the Civil War, then no—we are not currently engaged in a physical war over a defining constitutional and moral crisis.

However, if the comparison is any other period in the last 140 years, then yes. The ideological gap between politicians is at a post-Reconstruction high, our social identities have become deeply weaponized, and the level of personal, affective hatred between everyday citizens of opposing parties is higher than at any point since modern polling began.