Political polarization is higher than in recent decades by most modern measures, but not necessarily higher than at the most divided points in American history. It depends on how you define and measure it.
Here are the main ways researchers look at it:
1. By Modern Polling and Voting Data - Yes, It Is High
Most data on polarization only goes back 50-80 years, and on that scale polarization is near historic highs.
a) Affective Polarization: This is how much partisans dislike and distrust the other party, rather than just disagreeing on policy. This has risen sharply.
•Pew Research Center, the American National Election Studies, and other trackers find that since the 1970s-90s, the share of partisans who have a "very unfavorable" view of the other party, who would be upset if their child married someone from the other party, and who see the other side as a threat to the nation has increased significantly.
•The share of Americans who identify as consistently liberal or consistently conservative, with little overlap, has also grown.
b) Ideological Sorting and Congressional Voting:
•The DW-NOMINATE score, which measures ideology based on roll-call votes in Congress, shows the two parties in Congress are further apart ideologically than at any time since the late 19th century, and there is almost no ideological overlap between the parties. There are very few liberal Republicans or conservative Democrats left compared to the mid-20th century.
•Geographic and social sorting has increased - people are more likely to live near, socialize with, and get news from people who share their politics.
2. By Historical Comparison - No, It Has Been Worse
If you look at the full scope of American history, the country has been more deeply divided at other times:
•1860s - Civil War Era: Sectional division over slavery led to secession and civil war, which is a more extreme form of polarization than today.
•Late 19th Century / Reconstruction: Intense partisan conflict, political violence, and disputed elections.
•1960s - Early 1970s: Division over civil rights, the Vietnam War, and cultural changes led to widespread protests, political assassinations, and riots.
During much of the mid-20th century, from roughly the 1930s to the 1970s, the parties were less ideologically sorted and more internally diverse, which produced more bipartisan compromise but also masked deep divisions within the parties themselves.
3. Why It Feels Worse Now
Researchers point to several structural factors often cited for the recent increase:
•Media environment: Shift from a few national broadcast networks to fragmented cable, talk radio, and social media that allow people to select information that reinforces their views.
•Partisan media and primary incentives: A more nationalized media and primary election system that tends to reward appeals to the party base.
•Geographic sorting: People increasingly living in politically homogeneous communities.
•Negative partisanship: Voting and engagement driven more by opposition to the other party than by support for one's own party.
Bottom line:
If the question is "are Americans more affectively polarized and are the parties in Congress more ideologically distant than they were 30-50 years ago" - the answer from most data is yes.
If the question is "is this the most divided the country has ever been" - most historians would say no, the Civil War era and other periods featured deeper and more violent divisions.