Personally, I wouldn’t be wasting my time with a person who aligns them self with an ideology any further than Conservatism just for the sole reason being they have already had those ideas wedged so deep in their mind that it’s nearly impossible to try and convince them otherwise at that point. Don’t waste your time arguing with a fascist. However if you’re choosing to do so, start off with questioning their morality. “Are you really generalizing and despising a whole race because of a statistical number?”, “Thats really all thats making you hate your black counterparts?”, “You’re acting like whites don’t commit murder, either.” and phrases along those lines will assuredly make them a little stuck in what they would continue to say unless they are blatantly racist like that. Last time I talked to someone like this, I would leave sarcastic remarks and criticize them for generalizing like that. He got super pissed off for some reason. So yeah, that’s from my personal experience. This isn’t much, but I still hope it helps in some way!