So says David Brooks, according to this excerpt from Daniel Drezner.

It probably would be psychologically difficult for most Brown professors to share an office with someone who was pro-life, a member of the National Rifle Association, or an evangelical Christian. It's likely that hiring committees would subtly -- even unconsciously -- screen out any such people they encountered. Republicans and evangelical Christians have sensed that they are not welcome at places like Brown, so they don't even consider working there. In fact, any registered Republican who contemplates a career in academia these days is both a hero and a fool.

So too libertarians.