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

Whether political polarization is "worse" today than in the past depends entirely on which era you compare it to and how you measure it.

Political scientists generally divide polarization into two types: ideological polarization (differences in policy positions) and affective polarization (feelings of dislike, distrust, and hostility toward the opposing party).

By both metrics, political polarization in the United States is at its highest level in over a century, though it still falls short of the ultimate breakdown of the 1860s Civil War.

1. The Historical Context: Where We’ve Been

The Mid-20th Century: A Historical Anomaly (1950s–1970s)

If you are comparing today’s political climate to the mid-20th century, polarization is drastically worse. However, historians point out that the mid-20th century was actually a historical anomaly.
During this period, there was an unusual amount of overlap between the two parties. The Democratic Party contained both northern liberals and deeply conservative Southern "Dixiecrats". The Republican Party had both conservative midwesterners and liberal "Rockefeller Republicans." Because the parties were not ideologically pure, bipartisanship was common. In fact, in 1950, the American Political Science Association issued a report complaining that the two parties were too similar and that voters didn't have distinct choices.

The Reconstruction and Gilded Age (1870s–1890s)

If you look back to the late 19th century, the picture changes. Political scientists use a statistical tool called DW-NOMINATE to measure the ideological positions of members of Congress based on their voting records.
According to this data, congressional polarization today has reached levels not seen since the Reconstruction and Gilded Age eras. During the Gilded Age, the country was deeply divided over industrialization, immigration, inequality, and monetary policy. Hostility was fierce, political violence was common, and there was virtually no ideological middle ground in government.

The Civil War Era (1850s–1860s)

The ultimate high-water mark of American polarization is the Civil War, which led to the physical splitting of the nation and the deaths of hundreds of thousands of Americans. While today’s rhetorical division is incredibly high, the U.S. has not reached the point of armed, state-on-state military conflict. However, some historians and political scientists warn that we are seeing levels of "constitutional hardball" and institutional erosion similar to the decade leading up to the Civil War.

2. Why Modern Polarization is Uniquely Dangerous

While we have had highly polarized eras in the past, modern political polarization has several unique characteristics that make it particularly difficult to resolve:

A. The Rise of "Affective" (Emotional) Polarization

Historically, Americans could disagree on policy but still respect their opponents. Today, the division is deeply personal and emotional.
According to the Pew Research Center, the percentage of partisans who view the opposing party not just as wrong, but as "immoral," "dishonest," and "a threat to the nation's well-being" has skyrocketed. A 2026 study by the University of Cambridge tracking divisions since the end of the Reagan era found that US polarization over political issues grew by 64% since 1988, with almost all of that rise occurring after 2008.

B. Complete "Sorting" of Identities

In the past, a person’s political party was just one of many identities. A voter might have been a conservative, a Catholic, a union worker, and a Democrat. These overlapping identities served as a "cross-pressure" that kept people moderate.
Today, those identities have completely aligned, or "sorted". Race, religion, geography (urban vs. rural), cultural tastes, and political ideology have fused into two distinct "mega-identities". If you know where someone lives and what their hobbies are, you can predict their political party with high accuracy. This makes political disagreement feel like an attack on one’s entire lifestyle and culture.

C. It is "Baked In" and Year-Round

In the past, political tension peaked during election seasons and cooled down afterward. However, researchers from the Polarization Research Lab found that affective polarization in the U.S. is now "baked in". It remains consistently high before, during, and after elections, meaning there is no longer a post-election "cool down" period.

D. The United States is an Outlier

While polarization is a global issue, research indicates that the United States is polarizing faster and more intensely than other comparable democracies. A prominent study by economists at Brown and Stanford universities found that while some democracies (like Canada and Switzerland) have seen slight rises in polarization, others (like the UK, Germany, and Sweden) have actually seen polarization decrease over the last 40 years. The U.S. stands out as a stark exception in the speed and depth of its division.

Summary

Is it worse than ever? No. The Civil War remains the worst period of polarization in U.S. history.

Is it worse than it has been in the lifetime of almost every living American? Yes. We are living through a period of division that rivals the Gilded Age. Furthermore, because of social media algorithms, geographic sorting, and the alignment of cultural identities, today's polarization is more socially pervasive and personally hostile than at almost any other point in modern history.