They are not dumb, they just don't think the same way you do. There's a reason that evangelicals in this country vote Trump. It's not a logic thing, it's a faith thing. As an example, look at the big name Evangelical Preachers over the years. They get rich from church donations, then they do horrible things, they beg for Jesus to forgive them (and everyone else). And that's a viable solution. MAGAs believe in Trump the same way that they believe in those preachers... It doesn't matter what facts are out there, it's God's will.
Conservatives, generally, and MAGAts, especially, are lower-level-hierarchy thinkers. They're scared, for themselves, of basic things ... personal safety, base financial well-being They also feel weak and insignificant ... so, while they are paranoid about personal safety, they need a gun, rather than their own wits, to feel safe. They revel in a big arse military fighting on their behalf. And because they feel they had to overextend themselves to get their little pile of money, they're paranoid someone is going to take it from them, so they're on the lookout for any small possible "scam" to "cheat" them of it. That's why they focus on the exception of welfare fraud, for example.
As a part of being weak and insignificant, and focusing on base selfish things, they LOVE dumbing things down and looking to others to be their leader ... and tell them what to do. That's why organized religion works so well on them. "All this stuff is so complicated ... I can't figure it out and I can't manage my own behaviors ... I just don't know where we come from and why we're here!" Insert ... a god. He tells them why they're here and what they should do. And they follow ... or at least say they do. That's why the military appeals to them ... "this guy has a "rank" and he's going to tell me what to do, and I'm going to do it." Boom. And they have "gods" to follow there - their commanding officers, their generals and their POTUS ... and they latch on to symbols, as well. The flag, for example. They like to worship things. Specific things. Things that "tell' them what to do and who to be.
This is why Trump easily became their Messiah, and why they'll follow him, no matter what he does. He stands up and tells them how it is. So they listen. He's loud and brash, so he makes them feel powerful just by agreeing with him ... he's our leader and he'll show us the way. We should troll and own the libs? OK. It's just another cult, like organized religion. Worship "MAGA" ... worship Trump. He can tell them they suck and they're stupid, and they say ... "we suck and we're stupid."