The 1930s were full of violent protest - running battles on the streets between gangs of thugs on both sides (red vs Brown shirts). It helped Hitler portray himself as the law and order candidate.
Peaceful but overwhelming mass civil disobedience and protest is better. The time for that is now.
And I'm hoping we never reach the need for more than that.
As for violent German protests, I'm pretty sure taking away those violent opposition protests would not have prevented Hitler from taking power. Perhaps they needed more violence. And indeed they eventually did get more violent opposition that did defeat them, by the West's armies.
Perhaps more violence in the thirties might have prevented WWII.
And now much of that is virtualized or amplified and concentrated in terrorist incidents - like many other things in our technological society. Why would you expect political activity to have stayed the same when everything else is changing? Just as we don't go downtown to do all our shopping any more, many conflicts are carried out in cyberspace rather than in the street. go look at the comments section on major newspapers, they are a battleground for ideological dominance. There is abundant historical evidence that such battles are only a prelude to physical conflict.
Incidentally if you think violence hasn't already erupted then you're being wilfully blind. Here's a recent example and I could point to many more and famous examples, like that of Anders Brievik and his imitators.
I'm not saying it has not errupted (it has) I'm saying violence and the glorification if it (as in people sharing the punch a Nazi video) is a dead end and will definitely strengthen trump support.
The way to defeat him is to resist, massively, peacefully and persuasively - to persuade the nation that he is wrong, irrational and damaging everyone with insane policies like retroactive withdrawal of green card status.
I hope you're right, but I have to prepare for the very strong possibility that you're wrong and that he and his major cohort of supporters are not in fact amenable to reason and shared conceptions of fairness.
Peaceful but overwhelming mass civil disobedience and protest is better. The time for that is now.