An easy read, with anecdotal and statistical support. Correlation is not causation, so read this with at least a grain of salt. Bishop is not the first to claim assortative matching in areas other than human mating. While the net he casts covers many activities, his focus is largely on politics. Despite my doubts, I think his suggestion is closer to the truth than a previous comment blaming Sesame Street for the disappearance of the middle from American political life.

How wow, dudes! This dude Bishop, a reporter of some sort, has it all figured out!
Finally, dudes ! ! ! Like for sure, but it would have to be this answer, it couldn't possibly have to do with pathetic indoctrinated education, shows like Sesame Street, which evokes gullible brain wave configurations, and financed by Peter G. Peterson, private equity/leveraged buyout dude extraordinaire, responsible for offshoring endless jobs, destroying endless companies and livelihoods, and founding the Peterson Institute, dedicated to offshoring jobs, destruction of Social Security, Medicare and Medicaid, et cetera! And long-time producer of Sesame Street, Peterson's wife, of course!
Yup, I'm sure it has nothing to do with constant propagandizing by the Fake News Network of foundations, trusts and endless so-called // think tanks \\!
Thanks, Mr. Bishop, and what is your next Big Answer, sir?!?!?