A preference cascade?

Are we witnessing a "preference cascade" for Donald Trump in America and for "Brexit" in Britain? Glenn Reynolds defines that concept in his USA Today column, and concludes,

It used to be, of course, that the lower and middle classes were stuffy and constrained by social convention while the freethinkers at universities and in the ruling class got to experiment with unconventional ideas. If their experimenting got enough success, then it might eventually filter down to ordinary people. (The sexual revolution worked this way, more or less).

But now it’s our ruling class that is hidebound by political correctness, and it takes movement by the masses to give it permission to express a controversial view. That’s a major change, and it’s one that the ruling class isn’t likely to appreciate much. But having subjected itself to the chains of “acceptable” opinion, what can it do?

Read more here.