Liberals in Academia. Liberals Conforming. Coincidence?
Three takes
1) Robert Brandon - Academics are smart, and tend to be liberal. Liberals tend to be smarter
2) Glenn Reynolds - Most Academics are unoriginal
3) Arnold Kling - Liberals tend not to like responsibility, and academics tend not to need responsibility, so liberals end up as academics

My take? Where the hell is this liberals are smarter crap coming from? Yes, there a lot of dumb conservatives out there. However, of the truly intelligent people that I have met in my life, very few have been liberal. Almost all have ended up being libertarian. How do I reconcile this with the fact that almost all of my law professors are liberal? Well, almost all my econ professors have been libertarian, so like I said, the most intelligent people that I have met in my life have tended to be libertarian :-)

Seriously why are there so many liberals in academia? Obviously I don't believe that liberals are smarter. Nor do I buy the argument that liberals don't like to take on responsibility, mainly because it conflicts with my personal experience, and there is always a drive to change the world that many of those on the left possess (tough to view going to africa with the peace corp and working for an obscure tribal village as not wanting to take responsibility).

I think the best explanation is that the Academy rewards cleverness so long as it conforms to accepted norms. Further, social pressures of the university causes more students who tend to be susceptible to groupthink/believing acceptable things to become liberal than conservative/libertarian. Liberals, having a greater concentration of individuals who have a history of conformity, succeed better in a field that demands it, leading to the disparity.