Some of stuff attributed to Ms. Coulter make her sound crazier than a loon, and a mean one at that. But that's no reason for a college to cancel an appearance that some of its students obviously wanted.
She has the right to be heard, and the students who want to do so have the right to hear whatever she has to say. If other students don't want to hear her speak, even if they're vehemently opposed to everything she stands for, that's no reason to forbid her appearance. They can simply not come to the speech. Or lawfully "protest" outside the venue. Whatever makes 'em feel warm and fuzzy.
There is absolutely no excuse whatsoever for violence of any kind just because someone who you don't approve of is giving a speech somewhere. Don't wanna hear it, don't go! Whiny babies! Those precious little safe-spacer snowflakes need to go back home and live in their mama's basement.
Asbestos shields: Up. Flame away.