I think the point this article misses is it is not just words and ideas: given the opportunity, Nazis and their ilk WILL unleash a violent reign of terror that will dwarf what happened at that protest. Letting Nazis have a platform emboldens those who share their ideas to act violently, as we have seen so many times. 

Will punching an individual Nazi stop this? No. What will stop Nazis is determined mass resistance that will use whatever means necessary to stop such a vile, dangerous movement from taking hold. In the meantime, I have zero sympathy for Nazis who get punched, because guess what: given the opportunity, they'll punch a gay person, a person of colour, or political opponent, or worse.