Why are you so insistent that racism isn't nearly as determining a factor in American politics as Americans may believe?
I can understand thinking of classism as the mother of all -isms (even though sexism holds that distinction) and that racism is merely classism in camouflage (which I think it was at its origin but that it's long, long since taken on a life of its own), but you have to be what they used to call a vulgar Marxist to imply that culture has so little input in a nation's mass politics.
Because I don't think people go out and vote a certain way due to racism. Or those that do are a vanishingly small minority. I think people go out and vote for something that tangibly benefits themselves rather than against something.
Is racism in the US real and, well, huge? Of course it is. You'd have to be a simpleton not to realise that. But I don't think you can do much by just saying to people "stop being racist eh?" - you have to tackle the underpinning causes of it.
Here's a simple, undeniable fact - it might feel simplistic, but it's just simply true; if racism was the single biggest, massive, underpinning electoral issue and the reason a load of people vote Republican, Obama never wins the presidency. Sorry but he just doesn't. But he did, because he was simply trusted more on key issues that people cared about more than his skin colour.
For me, it really is all about living standards and class divide. The wealthy Trump support just care about tax breaks, like any Republican - the other stuff with him is all secondary. The poor Trump support simply care about their own lives. There's a subset of racists who'll vote for him, of course there is, but their numbers as a determining factor being that high? Sorry, just don't buy it, same as I don't buy "everyone who voted for Brexit is a racist" - they're simply not; they just voted the same
way as the racists.