I'm coming from the same basic perspective as you describe, and always tried hard to see people in the best light and sympathize with their concerns, but am no longer finding that possible in this situation, and it is disheartening.
The only explanation for the core MAGA supporters that I can come up with is that it is a sort of loose coalition of people that feel disaffected and judged by society for various reasons and want acceptance - and vengeance. It includes many people that are, e.g. sociopaths and racists, and want someone to tell them that being like that isn't bad, it's actually "protecting American from inferior people" or some such thing.
There is just no way that people don't realize that Trump is a malignant narcissist that lies every time he speaks, and tries to sadistically harm anyone that doesn't support him. The only explanation is that people don't like him despite that, but because of it- him being so awful, and proudly like that with no hint of remorse, absolves them of the lifelong guilt and fear that they might be bad people also, and instead frees them to also be proudly like that themselves.
Recently I've been reading a book about the history of the Jim Crow era in the south, and the extremely widespread brutal terrorism and mass murder, and I can't really reach any other conclusion than that those people just laid low for a while while they regrouped and strategized, but they're just as prevalent, violent, and racist now as they ever were, and they're done hiding. They see the Confederate/Nazi/Fascist dream of a totalitarian white ethnostate in their grasp, and they are ready to make it happen - they aren't ashamed for wanting that, and they aren't afraid anymore.
I get that this is a really dark view of current events, and I really hope it is not true, but at this point, I think it is delusional to pretend that it's anything but the most likely explanation and prepare accordingly.