I'm not sure what your point is here.
I don't think there is any particular requirement that anyone finds Trump's type of humour funny. Humour is very individual though it also has strong culture, class, racial, and other factors that influence how we receive it. In the end, what we find funny we find funny, what we don't, we don't.
What I was suggesting however is that the progressive middle classes, in the case of Trump and his voting base, tends to interpret the humour that is not native to their own group as evidence of stupidity, and it isn't. It's evidence of a different background. (They on their part also likely find the humour of the university educated progressive classes lacking. Which does not make it all dumb. Just differernt.)
It's fundamentally a lack of class connection. And it is at best a blind spot, and often a way to allow themselves the comfortable illusion that the opposition is all dumb dumbs. Which means they never even try to really understand the strategy or reasoning for the actions. It's why you can't find any half decent commentary on Trump's economic strategies in the progressive media, you have to go to some place like Unherd, even though there you can find socialist economists who will talk about it. But the mainstream progressive left is wilfully blind.