I want to stay friends with a white supremacist
Why do you want to be friends with a white supremacist?
I find them fascinating
Judging people without knowing them is wrong. If other people find out they might also call you a white supremist.
But what if I can help them change?
Still people have a problem with prejudice. You might not be able to change his mind, are you not worried you could maybe be persuaded by him?