I don't really like having to do your research for you on a topic everybody knows is common knowledge (at least for most people).
But it's not common knowledge because in everything you're giving me, none of it supports your argument.
You are trying to widen the parameters of what "preventing" means so much that any protest or criticism becomes an act of prevention, regardless if it ever actually prevents anything.
Your original argument was that Conservatives are being prevented from speaking. Yet, you couldn't produce a single legitimate instance of it that didn't involve a bigot like Coulter or Milo; people who rightfully earn the scorn, protest, and prevention.
You must have incredibly low standards for yourself, based on how you debate here.