The inside-the-law approach that works to some limited extent is public community rejection. Things like large groups showing up and standing with their back to the Nazis.
The method that has historically stopped Nazis like this involves getting some level of police cooperation and beating them up
There were several laws put in place in postwar Germany that specifically suppressed them. This was broadly effective, though I think the modern-day position of the AfD shows it was not completely so.
In the US, any such legislation would be struck down in court as unconstitutional.
So, it’s just not that simple.
Newsflash: some number of people are absolute shitbags.
If you let them take over and run the show it’s gonna get real bad.
Nazis are absolute shitbags. They will always be around in some number. You need to always suppress them so they don’t fuck up the good shit we have managed to eek out.
Well, yes, you definitely don’t want to let them take over. You want to demonstrate your own strength, and how much you outnumber them.
This is not preventing them from marching in some way, though. That is not doable, it would be illegal. It would also be counterproductive in our current climate of most people underestimating the actual danger.