Right now, cult of ignorance perfectly describes Trump and his supporters. It is just true.

I think his appeal has a lot to do with how much those elites despise him. I think the desire for someone Trump-like predates Trump by quite a lot. I see Obama as the embodiment of that smugness and Trump as a reaction.

As an example, "You didn't build that", while I get his point, it was poorly made and disregarded a lot of very hard work by the people he was talking down to.

That's why his supporters don't seem to care about his policies,flaws or ideology. They like him because those people hate him. That may look like cultish behavior because they change opinions based on his whims but I bet if he started acting like and was accepted by those "elites", his support would dwindle.

I think a lot of people look at the situation and don't understand it then just decide that his supporters must be stupid.

I think it can be multiple things, there are some Trump supporters who are very religious, some are just racists, some that are disenchanted with the way things are and want anyone to burn it down, some are as you described, and some that are so deep in the cult of personality that when confronted with evidence that contradicts their beliefs, they double down - there are multiple videos of this last one, like blaming Biden or Obama for some policy when Trump did it.