Do you ever read an idea and feel enlightened and envious at the same time? You simultaneously think, “Aha! That’s insightful,” and “Dang! I’ve been sniffing around this concept and haven’t quite nailed it like he did.” In this instance, it’s a concept that helps explain both the deep dysfunction of our political system and the deep discomfort that so many people of good will—on both sides of our political spectrum—feel with our political culture. 

It’s summed up in this tweet by a sharp lawyer I follow who tweets under the name “A.G. Hamilton.” 

If you click on the tweet you can read his entire thread, but his point rests on two key and obvious trends. First, the Democratic Party has moved quite decisively to the left, and the median Democrat has moved far more to the left than the median Republican has moved to the right. This chart, recently made famous in a column by progressive writer Kevin Drum, illustrates the point nicely: