I wonder if it has something to do with David Horowitz's exposure of the intellectually bankrupt left, whose adherents have used all of the dirty tricks at their disposal in order to suppress this man's freedom of expression.
In Mr. Horowitz's case, this is exactly what happened. He goes into some detail on this subject in his ESSENTIAL work Radical Son
Amazon.com Books RADICAL SON A JOURNEY THROUGH OUR TIMES FROM LEFT TO RIGHT
"Commies" provides some great insight into this nefarious world of back-stabbing, ideological litmus tests-that only apply to conservative thinkers, of course-and the general insanity of the system of higher education that prevails on most college campuses today.