@Demosthenes49 In the case of the CMC speaker, Heather MacDonald was prevented from entering the building because protestors blocked the entrance. There is no ambiguity in the language of CMC’s policy – you can’t “restrict movement” and you can’t “impede access” to a facility. I think that language would be upheld for a public university as well. I do not believe any case law exists which gives protesters the right to block an entrance or impede access to a building – public or private. And then of course you have the state laws and regulations to contend with which would also prohibit such interference.
In fact, if I recall correctly, a few years back the Chief Justice of the Supreme Court effectively reversed a federal court decision that said it was unconstitutional to prohibit demonstrations on the plaza directly in front of the Supreme Court entrance. Justice Roberts in response approved a U.S. Marshal’s regulation that banned demonstrations on that particular plaza. The reason given by the Marshal for the regulation was that it ensures “unimpeded ingress and egress of visitors to the court.”