I'll start off by saying that I've had family who perished in nazi concentration camps.
That being said, I couldn't care less about someone who aligns himself with Nazi views and belongs to a neo-nazi party. Same way that I couldn't care less about communists. If I hate him for those views, I'm only feeding the machine and continuing the progression.
His views also have no bearing on his competition. If these views lead him into serious legal trouble outside the ring, then he should be subjected to the conduct policy just like every other fighter, but he shouldn't be more aggressively looked at due to his views.