It's because to an individual, every single MAGAT is a biggoted fascist. They don't really care about all that stuff in reality, because he "tells it like it is!" which, to them, means all of the biggoted fascist nonsense that they have always believed. When they hear these things, confirming their core identities, they believe literally anything about the man.
Just hearing some public person very loudly shout the exact things they have always believed, and in no indirect, historically "polite" GQP way, replaces what remains of their barely-existent rational centers with every correct thing they suddenly think about a person. They were already primed to worship whatever single authoritarian strong man showed them the light, so their brains are always easy pickings. Whatever comes after that, it doesn't matter. They are captured and there is no turning back for these late-stage Nazi bitches.