You bring up a great point in that this might not even be really real in the way that it's portrayed.  But I think the more important issue is that whether he is a real nazi or not, hitting somebody because you disagree with their speech is antithetical to the traditional values of this country. Using violence to silence speakers that aren't a direct immediate threat to your safety basically puts you on the same tier as a Muslim who lashes out when you're not following the same beliefs that they are. Even if you find certain groups to be really repugnant: if you can justify walking up to Nazis and hitting them, then somebody can justify doing the same thing to other bad groups they don't like such as Communists. And pretty soon, peaceful discussion and civilization as we know it is over. Another important issue is that even if you can somehow justify walking up to Nazis and punching them, parts of the left label anybody to the right of basically Bernie Sanders as a Nazi. People holding even libertarian views or moderate views are seriously labeled as Nazis. So this mentality that its ok to hit people for disagreeing with your politics needs to get stamped out because it's not just a threat to a few people on the "far right".