Because the people voting for him are - themselves - childish, contrarian, armchair political pundits, who picked a jackass because they started out thinking it was a funny meme, but now have to pretend like they did it on purpose because someone said they were a fucking moron at thanksgiving and they're leaning into it out of spite.
Well, that's some of them. Some of them are just fucking idiots who think that the rising racist tide will lift their boat higher than the minorities that get paid more than them (because they're actually good at their jobs).