Part of it , is because we have a two party system. And these liberal leaning people.think Republicans are racist sexist homophobic etc. So by default, they end up voting g Democrat.
So even if some of these people see problems with what Democrats have done, they can’t vote Republican because then they would be voting for racism and homophobia, etc. In their minds that’s what they would be voting for. So by default, they vote Democrat.
So part of the challenge is to educate the smarter ones, to teach them to recognize leftist propaganda for the manipulative propaganda that it is. If they would just learn to think critically/analytically, they would be halfway there already.