I feel like I get to add a voice here, because outside of my exact city limits, everything around the Pittsburgh area (including the area where I spend 5 days/week at work) is
very working class and
very red.
They don't say the quiet parts out loud all the time, but they absolutely blame immigrants (legal and otherwise, so long as they're brown) for their troubles, they're infuriated at the idea of raising taxes (even on the very, very rich: they earned it! they worked hard for it! why do you hate success?), and a great many of them
hate unions nowadays.
Clinton's platform was dramatically better for them long-term, included training in jobs that would continue into the future, would include a higher minimum wage, more access to healthcare, etc, etc, etc. It wasn't perfect, of course, no platform is, and she definitely didn't do an excellent job of getting the message across, but the platform had an actual plan of how to help these people, with real, tangible goals to work toward.
Trump lied to them that coal was coming back, he assured them that they were correct that brown people were the cause of their problems. He promised their guns were safe and that he'd return the US to a place they recognized: whiter, straighter, with women put back in their place.
Do you honestly think that outside of a handful, most working class Trump voters actually looked at his/the GOP's platform and thought it would help them? Or do you think they just decided to follow someone who blew smoke up their asses and told them he'd make everything the way it used to be! Just like they remembered in the Good Old Days (that were only good if you were straight, white, male and Christian)!
I know there were a ton of articles about this afterward, but the biggest factor for especially rust-belt Trump voters was fear: fear of progress, fear of immigrants, fear of technology, etc. They're absolutely terrified of the world as it is now, and they're even more terrified that it's going to continue changing. They feel like they're losing their stranglehold on power and influence, they don't like that people who look and sound different from them have seats at the table now.
Trump looks down his nose at them just as much, if not more. He gave them no more than empty platitudes about how he would make life better for them, with zero actual plans of how he was going to do that. But he says the racist, sexist, illegal parts out loud, and his voters either like him because of that, or they just care so little about other human beings that they love him anyway.
https://www.vox.com/policy-and-polit...-voter-florida
The cruelty from Trump against people they see as "other" is part of the appeal. They may not all be clamoring to join the KKK, to be sure, but they decided that open racism was totally fine from a guy they were going to vote as President of the United States.