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

Is polarization worse now? I'll pull historical trends and research to compare today to the past.

Short answer: Compared to the recent past - the last 30 to 50 years - yes, dramatically so. Compared to the most distant past - the Civil War era - no.

Research distinguishes several kinds of polarization, but most measures show a sharp increase in recent decades:

1. By recent historical standards, polarization is at a modern high

Concrete Pew trends:

> Across 10 political values Pew Research Center has tracked since 1994, there is now an average 36-percentage-point gap between Republicans and Republican-leaning independents and Democrats and Democratic leaners. In 1994, it was only 15 points.

> In 1994, when Pew Research Center began asking... the average gap between Republicans and Democrats was 15 percentage points. By 2017... the average partisan gap... had more than doubled to 36 points

> Today 92% of Republicans are to the right of the median Democrat... while 94% of Democrats are to the left of the median Republican, up from 64% and 70% respectively in 1994.

Affective polarization - how much partisans dislike the other side - shows the same pattern:

> In 1994, they reported that 16% of Democrats and 17% of Republicans had "very unfavorable" views of the opposite party in 1994, whereas in 2014 those percentages had risen to 38% and 43%

A long-term Cambridge study using American National Election Studies 1988-2024 found issue polarization has increased 64%, with divisions broadly stable through the 1990s and early 2000s, before rising steadily from 2008 onward.

That study noted polarization may have begun to level off during Biden's term, although it remains far higher than in previous decades, and that 2008 was a major turning point.

2. Elite polarization in Congress is at a 150-year high

Data scientists measuring legislators' liberal-conservative positions by roll-call voting (NOMINATE scores) find:

> 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.

Another measure is the "overlap interval" - how many Republicans are to the left of the most left-leaning Democrat and vice versa:

> 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

By that measure, partisan elites in the U.S. are as polarized today as they were around the time of the Civil War.

3. The U.S. is polarizing faster than other democracies

A Brown/Stanford National Bureau of Economic Research study of 9 democracies found:

> In the study, Shapiro and colleagues present the first ever multination evidence on longterm trends in "affective polarization"... They found that in the U.S., affective polarization has increased more dramatically since the late 1970s than in the eight other countries they examined

> In 1978, the average American rated the members of their own political party 27 points higher than members of the other major party. By 2016, Americans were rating their own party 45.9 points higher than the other party

> Political polarization among Americans has grown rapidly in the last 40 years—more than in Canada, the United Kingdom, Australia or Germany

Cross-national research finds that while some countries show similar trends, the US shows the steepest and most consistent rise. Researchers attribute U.S. exceptionalism partly to increased party sorting by ideology, race and religion and to 24-hour partisan cable news.

4. By longer historical standards, not worse than the 19th century

Historians caution against calling this the most divided period ever:

> "The most divisive time in our history was in the years leading up to the Civil War"

> University of Virginia Civil War historian, Gary W. Gallagher, says that current divisions pale in comparison to those of the mid-19th century. Between Abraham Lincoln's election in November 1860 and the surrender of Robert E. Lee's Confederate army at Appomattox in April 1865, the nation literally broke apart

> Some political scientists have pointed out 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

In other words, measured against the 1870s-1890s Gilded Age, or the 1860s, today's congressional polarization is high but comparable, not unprecedented. Measured against the mid-20th century consensus era - roughly 1940s-1970s when overlaps were large and partisan animosity low - it is significantly worse.

> Scholars also note that elite polarization has outpaced mass polarization: Americans in general are less sorted into entirely opposing tribes on issues than elite rhetoric suggests, but elites and the most politically engaged citizens have become much more consistently ideological and hostile to the other side.