1. Well, to a first approximation, workers solidarity movements fare better in Europe where, until very recently, the population was largely homogenous and thus more receptive to solidarity; but also
2. Social media and the internet have flipped the script. It used to be that you had to hang out with the people you worked with, or lived around. As we know from decades of social science research (that was the impetus behind diversity initiatives), actual interactions with people of different races helps moderate racism. As you'd expect. [And that, of course, was one reason for segregation. ]
But you don't have to be at all interested in your neighbors any more. You can hang out with other people like you, no matter where you live. And then groupthink and affinity bias and racheting extremism takes over.
3. I know I'm being pessimistic as hell. You're trying to be optimistic. You're trying to see a future. I'm really struggling with that right now. In fact, I'm kind of struggling with a lot of things right now.