“ It is fundamentally ridiculous to assert that some alt-right propagandist be given the freedom to speak at a college (even a private one like Middlebury)”. Are you suggesting that Charles Murray (with whom I mostly disagree, by the way) is an alt-right propagandist? Because it was Murray, not Milo Y., who had a scheduled talk at Middlebury. If you do suggest that, then you are just speaking nonsense and you would help yourself by reading this NYT article. If not, please accept my apologies.
Totally fair. Murray is more of a neoconservative, and a Koch Brothers stooge, by way of his work with the American Enterprise Institute. As such, he is a propagandist, but not an alt-right propagandist. Based on what he has said and written, and who has funded his work in the past, he likely is a white supremacist, so he does share that with a lot of the alt-right hate-mongers, but he isn’t technically in their camp.
I agree that you can’t hold other people responsible for what an extremist minority does, and students have the right to protest peacefully, but it is also true that political passions and group dynamics interact in such a way that the vocal, radical minority often times succeeds in derailing the best arguments for a given position, and the progressive camp in the US is unfortunately suffering this right now.
Whether or not your observation is true is irrelevant. Students still have a right to protest. Any argument that suggests otherwise, or that attempts to harangue students into silence because it is virtuous to “challenge their ideas” or some other such BS is, simply, an elitist, fascist argument that aims to privilege the free speech of paid celebrity speakers over that of students.