People seem to be having a really bizarre misunderstanding/misinterpretation of what tolerance is. Tolerance simply means the recognition that everyone has the same rights, and even if we don't like or agree with what others are saying, we recognize that they have a right to say it. Anything less is not free speech - popular speech does not need to be defended. It's like during the Bush years when the neo-cons insisted we needed to set aside civil liberties because "war on terrorism." The thing is, civil rights are not just civil rights when everything is hunky-dory. Since it's founding, this country has almost always been in some kind of a war or conflict. It's when things are shitty that civil rights are the most important, because it shows just how dedicated to this country's founding principles we really are. And the thing is, now the "progressives" have every bit as much of a brain fart as the neo-cons when it comes to this free speech issue, because they seem to be under the impression that letting these people make fools of themselves somehow translates in to "OMG the Nazis have taken over and can do whatever they want!"
Uh, no, that isn't how that works. This is a nation of laws, and as much as they might say how much they'd love to do vile and nasty things, they can't. And yes, this does translate into the police "not doing anything and even actively helping them," and all because the other group of idiots keep trying to attack them. Tolerance does not mean support or acceptance.
And to the "doomed to repeat history crowd," part of what lead to the rise of the Nazis in Germany was the violence in the streets between them and communists. It allowed them to play the victim, and to play the "hero to the people" by protecting them from the communists. The anthem for the brown shirts, "Horst Wessel Lied" is actually about a member of the SA who was singled out and killed by members of the German Communist Party. And while I really doubt the Nazis will ever gain that kind of power here (and not for lack of trying, look up the Business Plot), it does still allow them to play the same victimhood game, and it'll probably lead to more restrictions on civil liberties thanks to all the assholes who think they're helping things by starting fights.