The mayhem in Charlottesville was pretty much locked in when the Swastika was unfurled and neo-Nazi chants about Jews filled the air. The antifa people are usually exaggerating when they go on about how nationalist=white supremacist=Nazi, but in Charlottesville that reasoning was not wrong.
Here’s the thing: if Nazis, real live Jew hating Nazis, join your protest and you let them, their stench will infect everything you do. Over on the left people are at pains to distance themselves from BlackBloc whack jobs. The right needs to do the same thing with Nazis.
This is not a question of free speech or free association: the Nazis have a perfect right to both; rather it is a question of whether of not the resurgent right wants to accept Nazis tagging along for the ride. If the right and alt-right people are OK with Nazis in their midst then they will simply lose the vast majority of their supporters. However, if they make it very clear that Nazis are unwelcome they can carry on an build support. And by “making it clear” I mean to the point that Nazis at right wing gatherings are more likely to be punched by alt-right people than antifa.
If the Nazis want to organize their own demos they can go right ahead; but the serious right need to make sure that there is no place for Nazis on the right side of the aisle.
(And, just to avoid confusion, America’s own KKK needs to be bunged in the same barrel as Nazis.)