Are liberal academics actually tolerant?

I've asked this question in different ways, over the years, particularly as it relates to the supposed free-and-open-debate of the academy. HERE is an interesting piece from The New York Times (by no means a reactionary publication) in which a black man reports facing more discrimination at the university where he teaches for being conservative than he faces in society in general for being black.

I've been keen on this issue ever since, as an undergraduate studying political science, I discovered that less than 10% of the professors in my department were Republican or conservative, while virtually all the rest were Democrats. This struck me as odd for an institution that supposedly valued diversity and vigorous intellectual exchange, both of which would have been much bolstered by having a few more conservative perspectives to broaden the conversation.

The above mentioned piece shows that new research has shed light on this skewing of academic faculties: it is a result of hiring discrimination. Read the whole piece for details.