I used to watch a lot of fringe science type videos for fun. My theory about this movement is its leaders are people that are bad at science but are charismatic and often very intelligent. They didn't fit into modern education system and didn't get good grades. For society that meant they are stupid and they resent the education system and scientific community for that. When they stumble upon the fringe science people they basically discover huge support network for people like them. The message is "no, you're not stupid, the rest of society is". They convince themselves that the science they don't understand is simply wrong and start creating their own, simple theories that spread in the community. The charismatic ones become new leaders and their theories get followers.

MAGA is pretty much the same. They are all seen by modern society as uneducated (because they are) and morally deficient (because they are). Then they discover this movement that tells them that they are actually superior to everyone else, it's just the evil system that discriminates them. Their leaders are the same, they are charismatic and cunning but definitely are not intellectual types. It's all just a big support group for dumb people where the mediocre rise to the top.