Not to further sidetrack this thread, so maybe in another, I'm very open to alternative lenses (less problematic? or at least have a less problematic messenger?) that provide a similar amount of explanatory power for the phenomena we see unfolding today.
Well, there are at least three approaches that I use when thinking about these questions.
1. Social psychology is where you are -- Le Bon is basically an early social psychologist. Hoffer was a dockworker with a lot of time on his hands, but his writing would be easily classified under that rubric. The problem I have with the social psychology approach is that it's bad at explaining why certain people and not others get sucked into the crowd. If you read Le Bon, you could come away thinking, "well, anyone could be a MAGA" and there's a sense in which that's true -- but also a sense in which MAGAs tend to have identifiable characteristics.
My usual disclaimer: I'm not a social psychologist. I haven't taken courses in social psych. I did read a lot about social psych when I was working on my thesis in intellectual history, which was a study about the development of social science and social psych was relevant to that. But my knowledge of the field is neither current nor thorough, and I know nothing about social psychology in a post-social media world. That said, I think that social psych will always have trouble explaining who and why, because of the nature of the field and its underlying theories. My view, partly informed but not especially.
2. There's also personality psychology, which is my favored explanation at the moment. This is the idea that people have different personality types, and those personalities are fixed at a fairly young age and are determinative of many adult characteristics, including political views. You can start with the "five factor model" and its relationship to the "authoritarian personality." Google gets you that easily. The advantage of this explanation is that it helps explain why evangelicals -- namely, that the evangelical milieu is heavily authoritarian. There's a lot of emphasis on hierarchy in that world, fixed and rigid roles, and most of all, discipline for young people rather than creativity.
As for reading in this field, you can't go wrong with Adorno -- except for the reading Adorno part. He writes in the Hegelian-Marxist German philosophical tradition, and while his work is considerably less opaque than that, it's not easy. The Authoritarian Personality is (not surprisingly) his most relevant work. What I've read has typically been in the form of journal articles, blogs, etc. I don't know of books in particular, but you could probably find them if that's what you want.
3. There's also an epistemic way of looking at it. This is more the product of my personal thoughts, and I'm usually quite syncretic in my thinking, so I don't know that I can recommend any specific set of works to address it -- but obviously epistemology is a well-regarded discipline and you could probably find work in this regard if you care.
By epistemic, I mean the way that evangelicals tend to think of knowledge in terms of revelation, rather than empiricism. A biblical literalist, after all, believes that the Bible is the ultimate source of knowledge, and the truth of the Bible was revealed to us by God in some fashion, so this is really a world view in which truth comes from acceptance of words deemed authoritative for reasons other than actual empirical correctness. And if that's your frame of reference, then why not believe Trump? What he says sounds ridiculous to us -- Haitians aren't, in fact, eating pets and the entire idea is utterly implausible -- but so too does the story of Noah's ark (which isn't to reject the story's importance; only to say that I do not believe there actually was a ship with two of every animal).
To put it somewhat differently, if your world view is predicated on beliefs you accept because X said so, then you're going to be much more comfortable with accepting ideas from any X. It could be Trump; it could Tucker Carlson; it could be Alex Jones; it could be Jim Jones. What you're looking for is someone to tell you how the world really works, just like the Bible or your pastor, and you've been conditioned to believe the revelations over your own lying eyes and ears.
I am 100% positive that there are folks on this board who can speak to this idea more fully than I can. I've convinced myself that this has to be playing some role, though the basis for that belief is shaky (which is why I bring it up -- it's not my usual M.O.) and I'm not really basing it on much but intuition and some conversations with my wife's evangelical family. So I will not assert this as a great theory, but I think its' worth some consideration
