Exactly. Our closet- and not-so-closet-authoritarians here think that just because "someone is making trouble" that therefore the government has a right to silence them. Not so. There have to be dire, immediate, imminent threats before one can claim that speech has to be silenced to prevent violence. None of that applies here. What we have is a "just so" way of looking at the world: the Nazis are bad people, bad people cause bad things, the world would be better off without them, therefore silence them "for the greater good". But the First Amendment was not written to promote "the greater good" as defined by authoritarians: it was written to shackle the arbitrary power of those in authority. No one wants to censor speech they agree with. It is precisely the unpopular speech that was intended to be protected by the First Amendment.
In thinking about this today, I wonder if the first amendment even assumes a certain level of personal responsibility that would have been a given in its time. There were certain things that would be said or not said in a given situation - for instance - the whole "yelling fire in a theatre" would not even occur tothe framers - "who would do that?" they would think - I wonder.
For instance, the Nazis of today's discussion would be responsible - not just for one day but within society for a long time - for what they said (or would have said, given the chance).
To others who may be reading - I apologize if I offended anyone. But the issue is personal responsibility. And non-race based expectations of appropriate behaviour.