It was a clear intent of action against the freedom of assembly, which is in fact part of the first amendment. The resolution was poorly written as well, being such that it would potentially oppose itself. If they want to take a stand against racial hate, that's fine, but a resolution needs to be in line with the principles of the first amendment and it needs internal consistency. It also needs to signal for action to be made, action that's feasible.
Is there some rhetorical point hidden in there that I'm missing? Because the logic of "defend x, get called an x" seems dubious and fallacious. In a comparative view it's even more easy to disprove by comparing views, which makes it even more silly. More so it's just an ad hominem attack trying to bypass argument.