Why upwardly mobile immigrants vote Democrat: I bet you can predict pretty accurately whether someone votes Democrat or not by knowing if he views himself as an outsider. The Democrat Party is the party of outsiders. The most Democratic voting bloc, blacks, see themselves as a marginalized group. Whites who loathe the idea of wearing a suit and tie are usually liberal voters. Many Jews still see themselves as outsiders (but that has a lot more to do with history than current realities). They vote 3 to 1 Democrat.
This is a serious problem when it comes to the issue of immigration. New immigrants are by definition outsiders. Moving to the inside--and I'm talking here about something psychological and not economic and social--is not easy for immigrants, especially if they are not white. As I have shown in recent posts, non-white immigrants move left as they move up economically and socially.
Someone who sees himself as an outsider also perceives himself as weak--the inside is where the power is. He naturally joins up with other self-perceived outsiders to play the role of David against Goliath. He is both insecure and morally superior at the same time. His stance is oppositional: he wants to tear down whatever it is that the giant wants to hold up. That role is a an alluring one, and the psychological payoff is large enough to keep its hold on a person, even after achieving economic success. The role is so appealing, the children of non-white immigrants are likely to adopt it, even though they were born here and may have enjoyed an easy life.
People on the Right, by contrast, have no such insecurities: they belong here and they know it. The guys in suits are not your enemies: you're on the same team. But it is much easier to get to that place psychologically if you are white and Christian.
I say Christian because I can think of two examples where it's not just about race. I mentioned already how many Jews see themselves as outsiders, even though they are white. I showed earlier that Filipino immigrants are one of the only groups to move right as they assimilate. That may very well be due to the fact that they are overwhelmingly Catholic (in addition to being economically successful).
My comments so far have focused on an individualistic orientation, which shows my Western bias. Non-white immigrants are probably more clan-oriented than their European counterparts, so they might simply vote Democrat because they are concerned about the ease with which family members and co-ethnics can move to America in the future, and the Democratic Party is reliably an open borders party. Clan loyalty for these folks trumps economic interest.
You might respond that if non-whites are less individualistic, perhaps that is the reason they move left after immigrating here. There are a couple problems with that idea. It might be able to explain why they arrive here more collectivist than the average American, but why would they move farther left as they assimilate? Second, they might be more clan-oriented than Europeans, but one wouldn't expect them to be more big government than European immigrants who come from countries more liberal than the U.S. And perhaps the most important item is the direction they move after they get here, regardless of their politics when they arrive. Non-whites move left as they move up; Europeans do not. Something about the experience here convinces successful non-whites that the Democrats better represent their interests, while high-income European immigrants do not feel the same way. Successful people from Europe appear to be focused on economic concerns like low taxes, while their non-white counterparts are insecure about their place here in America, and they worry about relatives and co-ethnics who might want to emigrate in the future.