Whether it was Charles Murray’s Coming Apart or John Edwards’s Two Americas, the story of our increasing class segregation has been told repeatedly and persuasively for 20 years.

College-educated men marry college-educated women, they live next door to other college-educated couples, and they all send their children to college. The great sorting machine that is college means increased “assortive mating” (elites marrying elites) and skyrocketing geographic segregation by class — which, of course, perpetuates the whole coming apart of our two Americas.