ARTHUR BROOKS: Bipartisanship Isn’t For Wimps After All.

Let’s start by considering what has happened. First, the average American is becoming more ideologically predictable. A Pew Research Center study from 2014 shows that the share of Americans with “consistently conservative” or “consistently liberal” views has more than doubled in the last two decades to 21 percent from 10 percent.

Second, despite the talk about divisions within the Democrats and Republicans, both parties are becoming purer ideological vessels, rather than mixed coalitions that cover broad spectra. In 1994, nearly 40 percent of Republicans were more liberal than the median Democrat, and 30 percent of Democrats were more conservative than the median Republican. Today, those numbers have plummeted to 8 percent and 6 percent.

Third, we also don’t like one another very much. Thirty-eight percent of Democrats have a “very unfavorable” view of Republicans, and 43 percent of Republicans hold that view of Democrats. About half of “consistently liberal” Americans say most of their friends share their views, and about a third say it’s important to live in a place where that is so. For those who are “consistently conservative,” these preferences are even more pronounced.

Furthermore, there is a Polarization Industrial Complex in American media today, which profits handsomely from the continuing climate of bitterness. Not surprisingly, polarization in the House and Senate is at its highest since the end of Reconstruction in the 1870s.

Predictably, this polarization has led to significant political discrimination. A paper published last year in the American Journal of Political Science shows that discrimination against political opponents is real and pernicious.

The funny thing is that many years ago — long before I was born — the American Political Science Association called for more ideologically pure parties. As usual, when you listen to political scientists, the result is disaster.