I think you are putting far too much into this "Godwins Law" thing. Just because Hitler is viewed as one of the worst people in history, doesn't mean he was the worst. Attila the Hun or Nero would have a good chance at the title if they were more recent.

But at the core of this argument is who has the right to decide what beliefs are allowed and what ones are not? For example I'm against ISIS, but think I have no right to suppress their speech. But I'll happily try to convince someone that the ISIS ideology is evil.

> as a core feature of their ideology while the others do not.

They seem to be exceptional, but if we curtail their speech that means it leaves other, undoubtedly less offensive, speech to be up for negotiation. For instance I'd be pleased to see some of your authoritarianism curtailed if it wasn't for ideals of freedom of speech.

Actually, racial and moral superiority were a big factor in the ideology for enslaving and killing native americans.

They probably do in places which suffered from it (Ukraine).

America was not the first or last European colony. Mexico was a colony, Brazil was a colony with even worse racism -bad things happened and continue to happen everywhere. Slave trade continues in the middle east. Today. Read up on what Latin American colonies did to the native populations. It's not different. They didn't have confederates.

I don't see how any of that should subjugate free speech.

Murderers have free speech --I'll wager more than a few victim's families wish they did not. I believe they should still have that right.

Should we go to Japan and also try to shut down the speech of those still in support of the imperial campaign in China, one of the most atrocious incidents of all of WWii?

You are right about the countries that suffered from Communism. East European countries, or Poland at least treat Nazism and communism as equally evil. There even is a passage in Polish Constitution (Article 13) that makes both Nazism and Communism exceptions from the free speech rule.