Those idiots wouldn't know a real NAZI if they fell over one. What bothers me is why aren't these people being called out and told to get lost by other protesters. If I was holding a protest for something I would be really pissed if a bunch of NAZI's showed up and tried to catch a ride on what I was doing.
"A man is known by the company he keeps"
Aesop
They have been called out in some cases. There's been video posted online of somebody wearing a mask and holding a nazi flag being told to leave by several protesters. Unfortunately, you can't physically make somebody leave a public area. That's called assault.