I found the clip via Bryan Caplan.
Like Caplan I’m not convinced this is a serious problem. It is a real issue, but not an actual serious problem.
As I explained in The Case Against Education, educators simply aren’t very persuasive, so they do far less intellectual damage than you’d think.
In the humanities and social sciences what matters more is that you attended uni, not so much what you actually learnt (or didn’t learn).
One problem I do have with Daniel Klein’s argument is that if the mechanism he describes is correct, then there are too many (not too few) non-left academics in academia. All up, however, an interesting presentation.