Why are Most Professors Leftists?

That has been a hot topic of late. In today's Pope Center Clarion Call, seven professors who are not leftist offer their thoughts on the thesis that the job of professor just doesn't fit the image that conservatives and libertarians have of themselves. I find that explanation to be weak. There are probably just as many conservative and libertarian types who are drawn to intellectual work -- teaching, research, writing -- as there are leftists, but knowing that the academic world is largely hostile, they largely do that work in other settings.