Americans are too worried and, at the same time not, worried enough about political polarization. Ideological rivalry is a good thing, not a bad thing: It's the reason for democracy, not a drawback of democracy.
However, when rivalry hardens into a sullen standoff — not a contest of ideas but a bloody-minded refusal to engage — you have a problem. And to put it mildly, the U.S. has a problem.
The Pew Research Center's new report on the polarization of U.S. public opinion is essential reading. It documents the growing ideological distance between Democrats and Republicans, not just in Washington but in the country at large. The information is fascinating and disturbing — but it doesn't do justice to the pathology it's describing. You could put it this way: The quantity of polarization isn't the main thing; what counts is the quality of polarization.