That would be Montana High School principal Tom Stack, who uninvited the conservative co-producer of "Schindler's List," Gerald Molen, to speak at Ronan High's commencement ceremonies. Stack, of course, isn't talking, but even the Superintendent concede's it was Stack's personal belief system that led to this injustice.
Full disclosure: I do know of cases where influential conservatives attempted to stifle liberal voices. But I can honeslty say that my personal experience is that liberals trying to deprive conservatives of a venue outnumber the reverse by about 50 to 1, at least. And there is no reason to believe Molen was going to deliver a political message.
In fact, I've been invited to speak at events where I'm clearly asked to keep the message apolitical, and I always do. Conversely liberals are seemingly incapable of keeping politics out of an public speaking opportunity they get. Consider what students are exposed to eight hours a day at public schools and then the very thought of them being exposed to conservative message for the length of a commencement speech sends a school principal into panicky censorship.
Speaking of free speech: now of course, the principal exercises his right to clam up.