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

Most evidence points to yes — by many measures, U.S. political polarization today is more intense than at any point in the last 50-150 years, though there's nuance to that claim.

Evidence that today's polarization is unusually severe

In Congress/among elites: a Pew Research Center analysis finds that, on average, Democrats and Republicans are farther apart ideologically today than at any time in the past 50 years. The ideological overlap between the parties that used to exist has essentially disappeared — whereas there used to be many Republicans who were less conservative than the most conservative Democrat, and vice versa, there is no overlap today; the most liberal Republican is still more conservative than the most conservative Democrat. The number of moderates in Congress has collapsed from roughly two dozen moderate Democrats and Republicans on Capitol Hill, a stark contrast to the more than 160 moderates that existed in 1971.

Among the public (affective polarization): This is the "dislike of the other side" dimension, and it has also hit record levels. Affective polarization – partisans' dislike and distrust of those from the other party – has reached historically high levels in the United States. Partisan hostility has sharply escalated recently: in 2022, 72% of Republicans and 63% of Democrats viewed the opposing party as more immoral than other Americans—up dramatically from 47% and 35% in 2016.

How Americans perceive the country: Americans increasingly see the country as more divided than at any time since the Civil War. A 2024 Gallup poll found a record 80 percent of U.S. adults believe Americans are greatly divided on the most important values, while just 18 percent believe the country is united, and not only is the percentage of those who believe the country to be divided higher than ever before, but the view is held broadly consistently across gender, age, race, political affiliation, and educational attainment.

International context: This isn't just a U.S. story, but the U.S. is an outlier. The US has experienced the most rapid growth in affective polarization among the general electorate since 1980 among the 12 OECD countries considered in a 2024 study, with five other countries experiencing smaller increases and six experiencing declines.

Historical trajectory: A Cambridge study tracking data through 2024 found this polarisation may have begun to level off during Biden's term, although it remains far higher than previous decades, with statistically significant increases in polarisation on every issue studied.

Important caveats

It's not a simple story of "worse than ever, full stop":

Bottom line

By the standard social-science metrics political scientists use — congressional voting records (DW-NOMINATE), partisan "sorting," and affective/emotional hostility toward the opposing party — the U.S. is more polarized now than at any point in the modern survey era (since the 1970s-1990s depending on the measure). The main exception is the Civil War period, which remains the historical high-water mark for division severe enough to produce actual civil conflict. Some researchers also caution that the perception of an unbridgeable divide may outpace the actual gap in policy views, even as identity-based tribalism has genuinely intensified.