If white supremacists can believe contradictory ideas and still be white supremacists, then how are we to determine who is and isn't? By this logic there's no evidence you could give me to prove you're not a white supremacist since contradictions. I don't mean that as a personal attack, but I hope you see how untenable such a line of thinking is.

Also, I do understand the possibility that someone could claim to believe one thing and not actually believe it. It simply requires a higher burden of proof.