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

The evidence suggests political polarization in the U.S. is indeed worse than it has been in recent memory (the last several decades), though the picture becomes more nuanced when you look at the full sweep of American history.

By most modern measures, yes—it's gotten significantly worse

Elite/congressional polarization: Using DW-NOMINATE scores (the standard method political scientists use to track how Congress members vote), researchers have found that in the 1980s and 1990s, the polarization levels are generally smaller than the levels in the 2000s and 2010s. Following a period of relative balance mid-20th century, ideological distance between the parties began to grow during the 1970s to the extent that Congress is now more polarized than at any time since the late 1870s Reconstruction Era.

Affective polarization (how much people dislike the other party, not just disagree on policy) has grown sharply. Using the "feeling thermometer" scale from the American National Election Studies, in 1978, the average American rated members of their own political party 27 points higher than members of the other major party; by 2016, that gap had grown to 45.9 points. Other data show the gap widening even further—from 27 points in 1978 to 56 points by 2020.

Ideological consistency: Pew Research data shows the proportion of Americans expressing consistently conservative or liberal opinions increased from 10% in 1994 to 21% in 2014, while ideological overlap between partisans significantly declined.

International context: This trend appears distinctly American. Political polarization among Americans has grown rapidly in the last 40 years—more than in Canada, the UK, Australia or Germany, and notably, while polarization also rose in Canada, New Zealand and Switzerland (to a lesser extent), it actually decreased in the UK, Australia, Germany, Norway and Sweden.

But some important caveats

The Civil War era was worse. Historians and political scientists generally agree although there is a case to be made that America's most divided days came during the Civil War, polarization has no doubt reached striking levels in the present moment. Some scholars note that viewed within the context of data from the last two centuries, today's levels of polarization are not such an alarming anomaly compared to those occurring during the time of slavery.

Policy positions may not be as far apart as they seem. One important critique: that doesn't mean politicians are farther apart on policy issues than in the past, according to political scientist Frances Lee. What is often missed are changes in the scope of policy issues over time—many of today's contested votes are narrower than something like 1960s civil rights legislation, which makes historical comparisons difficult.

Ordinary voters may be less divided than elites. Interestingly, the general public is less divided on a range of issues than in the past, with many policies having bipartisan support. And even amid rising hostility, Americans are less likely to express negative feelings toward someone of the other party if told that person doesn't care much about politics, or if reminded of shared identities.

It may feel worse than it is. One researcher cautioned that polarization in the US can feel much worse than it is—political groups have moved further apart in recent years, but these divisions may be amplified by media and social dynamics beyond the underlying numbers.

Bottom line

By virtually every modern quantitative measure—congressional voting patterns, partisan animosity, ideological consistency—polarization today is worse than at almost any point since reliable data collection began in the mid-20th century, and the U.S. is polarizing faster than peer democracies. However, it likely isn't worse than the most extreme historical episode (the Civil War era), and some scholars caution that comparisons across eras are tricky because the nature of political conflict has changed even as measured "distance" between parties has grown.