You can just say “well they’re stupid that’s what you get” or you can ask yourself why aren’t we getting these people on board while some greasy billionaire can?
I don't necessarily like to just dismiss people as stupid, but a lack of education and the ability to understand complex issues is both a big issue for these people and a reason why the greasy billionaires can get them on board. Convincing someone that them paying some of their money into a union will actually result in better working conditions and more money for them - rather than just being poorer - is a lot harder and takes more understanding on their part than someone convincing them there's less money to go around because there are more immigrants, for instance.
On top of that, people like to be able to absolve themselves of personal responsibility if they are given the option to. That's not exclusive to right-wing people, but when that's coupled with people wanting simple "explanations" because they don't understand more complex systems with all their consequences, knock-on effects, etc, it makes it easy for right-wing politicians and media to offer simple scapegoats and get people on board.
To use the immigrants example again: not only is it not your average right-wing voter's fault in any way - it's the immigrants' fault - but also, they don't personally need to do anything to fix the issue, they just need to let the right-wing politicians get into power and it'll all be solved for them. It's all very comforting for them - much more so than being told it's going to take ten years and some work on their part to improve things.