One of the things I read about that, is that people tend to take an “average position” between all the opinions they hear. It used to be that the opinions you’d hear would be based on serious media, and your close circles. But much of the media has gone to shit, and social media amplify crazy people because it’s good for engagement. So you end up hearing about the crazy position of lore as much as about the rational one. And that does influence a lot of people.
Even here in Europe where there are genuine left wing parties, where there’s proportional representation, where we have mistly functional education, labour class people are voting for folks who blame poor people and immigrants for everything that goes wrong. I think part of the blame is with tabloid style media and social media magnifying formerly fringe opinion. Just saying that having a real alternative for the populist right, might not be enough.