Some curious opinions here. I was almost wondering how the original video was racist but then we got the epithet at the end, and whatever that shit about white privilege was (it is a silly notion that some subscribe to, and from my understanding of no real relevance in that situation). Not sure it was racially motivated at this point as opposed to garden variety crazy (though the preparation phase speaks to something) but I will give it the benefit of the doubt if you want. One crazy does not a pattern make. Indeed I would say the west is probably the least racist place on earth, with the possible exception of scientific bases somewhere cold -- most people don't give a flying fuck what you are and will go with the content of your character, as it should be, and have pretty much been taught that and lived that since birth (or possibly the birth of their parents).
Where would you possibly have got that impression? If this is about the punch a nazi thing again then if they start by all means punch back if they are still a threat (though I would encourage a modicum of situational awareness, awareness of your abilities, and note that it is called fight or flight for a reason). If you think they have some strange ideas about how the world works then by all means tell them that -- the very same thing that allows them to espouse their nonsense allows you to say it is just that. Trying to shut people down and drive them underground seldom works though -- as the great saying goes sunlight is a wonderful disinfectant and there are myriad examples of it working. The one that instigates the fight however is the arsehole, if you want to do the "be the bigger man" thing and not rise even then (something that schools seem to go in for these days) then so much the better.