so many of them would rather make life hell for the “bad people”

A lot of the voter polls in rural neighborhoods are migrant workers without voting rights in the district. A lot more are too young to vote and not interested in sticking around long enough to set down roots in a poor community. And a healthy slice more than that are Company Town employees, who get a great deal of their political knowledge from their bosses.

I don’t understand how people can be so hateful

Fear leads to anger. Anger leads to hate. The first step is terrifying people, often with very legitimate concerns. Then comes misinformation and misdirection, scapegoating and bigotry. And finally, you just pound on those priors knowing full well people aren't going to fact-check you on every rumor and innuendo when you're telling them something they've been primed to believe.

Communities with very real and persistent drug abuse problems get sold on the "Evil Mexican Cartels ruined your town" mythology by sprinkling it with half-truths and selective reporting. Communities that got de-industrialized in the 80s and 90s are told to hate East Asians for "stealing" their jobs with cheap foreign labor and unfair business practices (that the employers still managed to profit off of). Communities of Jews are told to hate Arabs and communities of Arabs are told to hate Africans and communities of Africans are told to hate Jews, because the Scary Outsider controls the financial system that's driving everyone in town into bankruptcy.

And always, forever, there is the Specter of Communism. The Authoritarians in the big evil government (not the military! not the cops! the evil foreign blue-haired trans tankie bureaucrats) coming to take away whatever prosperity you have left.

Simmer people in that soup for long enough and they'll all come out spitting hate, because its the only thing they've ever known for years and years and years.