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

Polarization is up — but how it compares to history depends on how you measure it. I'll pull recent research to put today's divide in perspective.

Yes - by most modern measures, but with important historical context.

The short answer

Political polarization in the United States is worse than it has been in the past 50-100 years, and at levels not seen since the 19th century, but it is not worse than the period immediately before the Civil War.

> Republicans and Democrats are more divided along ideological lines – and partisan antipathy is deeper and more extensive – than at any point in the last two decades

> What I've found is that polarization has been steadily getting worse since the early 1970s. Today, we've hit the ceiling on polarization

In what ways it is worse than the recent past

1. Ideological consistency and sorting:

Pew Research Center combined responses to 10 political values questions asked since 1994 to create a measure of ideological consistency:

> The overall share of Americans who express consistently conservative or consistently liberal opinions has doubled over the past two decades from 10% to 21%
> Today, 92% of Republicans are to the right of the median Democrat, and 94% of Democrats are to the left of the median Republican

That overlap has shrunk dramatically. Twenty years earlier, only 64% of Republicans were to the right of the median Democrat, up to 92% today

Pew found separately that:

> the average party gap on ten policy questions grew from 15% in 1994 to 36% in 2017

And according to research cited by Pew tracking:

> Democrats and Republicans are more ideologically apart than they have been at any time in the past fifty years

2. Affective polarization - disliking the other side:

Scholars distinguish between ideological polarization (differences in the policy positions) and affective polarization (an emotional dislike and distrust of political out-groups)

Analyses show:

> political elites have adopted more extreme positions on core political issues in recent decades, while polarization among voters has become mainly affective rather than ideological

That affective dislike has risen sharply:

> In 1994, ... just 17% [of Republicans] had very unfavorable opinions. Similarly,... just 16% [of Democrats] had very unfavorable views. Since then, highly negative views have more than doubled: 43% of Republicans and 38% of Democrats now view the opposite party in strongly negative terms

Later tracking found:

> in 1994, about 16% of Democrats and 17% of Republicans held "very unfavorable" views of the other party. By 2022, those numbers had jumped above 60% for both sides

More broadly:

> Affective polarization — or, as one paper describes it, “the tendency of Democrats and Republicans to dislike and distrust one another” — has also steadily increased since 1980

> Such affective discord has increased sharply in recent years, and today a majority of partisans view the other party very unfavorably

The U.S. is also an outlier internationally:

> Political polarization is higher in the United States than in any other advanced country for which we have comparable data

3. Elite / Congressional polarization:

The most common academic measure is DW-NOMINATE, which measures legislators' liberal-conservative positions based on roll call voting records.

> It has helped confirm the narrative of growing polarization with hard data – showing that Congress today is more divided than at any time in the last 150 years

> The results from DW-NOMINATE indicate that the level of polarization in Congress is now the highest since the end of the Civil War

USC researchers summarizing that data said:

> Following a period of a much more balanced Congress during the middle of the 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

One way to see this is the "overlap interval" - how many members of one party are more moderate than members of the other:

> Today, the overlap interval is zero
> In the 1960s, for instance, you had intervals where about 50 percent of the legislators in the two parties overlapped

In what ways it is not worse than the distant past

Historians emphasize that the mid-20th century (roughly 1930s-1970s) was an unusually low polarization period, making today look extreme by comparison, but not unprecedented over 250 years.

> According to American political history expert and professor of history Randall Miller, Ph.D., it's not even close. "The most divisive time in our history was in the years leading up to the Civil War," he says. "In the mid-19th Century, differences were so profound representatives carried weapons into Congress."

> As a historian who has written and taught about the Civil War era for several decades, I know that current divisions pale in comparison to those of the mid-19th century

That era involved fundamental disagreements about slavery and federal authority that nearly tore the nation apart, with physical violence in Congress itself.

Historians also note that the degree of partisan polarization is generally considered much higher today than in the 1970s, but that earlier period was also characterized by major crises of confidence, while the Civil War era involved sectionalism and organized conflicts on a scale far greater than today.

In other words: the current period is the most polarized since the Civil War, because the Civil War and Reconstruction were even more polarized. The relatively bipartisan, overlapping middle of the mid-20th century was the historical exception, not the norm.

> Historian David Brady notes that partisan voting in Congress represents "the historical norm rather than the exception."