The psychology behind Trump is interesting. I suspect he genuinely is this stupid and believes the stuff he says, and he doesn't have a large enough vocabulary to get into genuine discussion with people about topics. It's all formulaic. You could be talking about taxes or shipping or dinosaurs and Trump is an expert on every subject. The way he attacks people is formulaic, they are losers or bad people, not very good at their job. He never emotionally evolved from being an 8 year old in the school playground. Another possibility is that he's just surrounded and guided by people that know his shtick works, they let him loose, they know MAGA army will lap up every single word, the content is irrelevant, it only matters that Trump is saying it. He may have been used as a tool since day 1.