@Jaichangecentfoisdenom
TBH, so many of us are asking the same questions. We can't really understand how the country came to this pass, either. I could posit theories but I'm not a sociologist nor a political expert. I can only think from a 'personal point of view' so here it is:
So much of what is 'wrong' with this county IMHO goes all the way back to Reaganomics and the 'Greed is Good' beliefs of the '80s. Trickle down didn't work and the Wall Street Wolves fucked over a great many people with Ponzi schemes and insider/rotten dealings and the majority of them just walked away with their cash lodged off shore. Many of the people who were fucked over were people who lost it all and saw the rich get richer. Some of them admired the rich (like Trump) for pulling it off. Instead of decrying it, they wished they had the means to do it themselves or had friends who would do it for them. It created that 'I've got mine, fuck you' mindset along with the feeling of "I got ripped off, someone needs to PAY". Add to that the inherent racism in many parts of the country. It had been simmering for nigh on 30 years and along comes Trump in 2015 and promised them all that they were 'victims' and that he'd deliver vengeance and riches. He gave them someone to hate and blame (those 'others') rather than blaming themselves for foolish decisions based on greed or just chance and misfortune. With the backing of fringe media and foreign 'assistance' he was able to spread his message. I'd do the usual comparison to Hitler, but we all already get the similarities.
His followers, from the redneck in a Kentucky 'holler' to an Ivy league graduate in a mansion, are only seeing what they want to see, what they think will benefit them. They don't give a rat's ass about their neighbors or those poor people living in shacks or tents. They think those people need to be 'gone' and they don't care how as long as it doesn't dirty their own lily white hands. And that people who want to help the helpless or less fortunate are commies or socialists. Because "I'm alright Jack, I've got mine".
As far as Evangelicals, I think the most radical of them back him because they think he's the Antichrist and will bring about Armageddon and the 'End Times'. They don't want him because he is 'good' they want him because they think it'll hasten the Rapture. The other Evangelicals, those who turn away from the truths we see of minorities/migrants being demonized, 'othered', and subjected to violence and maltreatment, need to remember the words of Jesus (Matt 25:40); "As you do unto the least of these my brothers, so have you done unto me" and also 2 Cor 5:10; "For we must all appear before the judgment seat of Christ, so that each may be repaid for what he has done in the body, whether good or evil".
Thus endeth the sermon for today.
TL;dr "Hell if I know, but I've got theories."