Suppose Martin Shkreli wanted to go on a diatribe in Hillary Clinton's bedroom. Would her excluding him from her domicile be a violaton of his first amendment right? Obviously not.

Now suppose he were already invited to her domicile, but she and Bill found him annoying so they told him to either stuff it or leave. Would that violate his first amendment right? Also no.

Now replace the Clintons and Shkreli with Stanford and the protesters, respectively.