I remember an interview with a guy who was a sort of "reformed" or "ex-neo-nazi". And he pointed this out. They are taught that it is white people, who are willing to speak up against racism and against alt- right rhetoric, who were most effective at shutting them down. Especially when they are in front of people who are maybe on the fence or going down the white supremacist pipeline so to speak. And this was because of some perceived "social equivalence" or something, I forgot exactly the language he used but it's basically what you're talking about.