That's the truthy story, but not the accurate one. Trump voters have higher than average incomes and less than average unemployment than the general population. The downtrodden are not who are propelling his campaign, even if it's a convenient lie we tell ourselves, because what educated person would support this man? Hence the conclusion about race.
I think you're overlooking the partisanship angle. I know two intelligent, worldly and only-kinda-racist rich white people that are voting for Trump. They're not voting for him because he's racist or because he wants to build a wall - they're voting for him because he's the Republican candidate, goddamn it and that's what we do. Yet despite all that, Republicans are still with him. Which is why the election is so close.And you couldn't have come up with a better individual to test that loyalty. Donald Trump is a recent convert to conservative ideology, which he expresses with absolutely no evidence of sincerity. He offers something to alienate every key constituency in the GOP, whether it's his occasional forays into isolationist talk (anathema to the neocons and other national security conservatives), his protectionism (abhorrent to the business conservatives), his libertine lifestyle and lack of religiosity (a no-no with the Christian right), or his lack of concern with cutting spending (distressing to the Tea Partiers). Then there's the fact that he is, in nearly every way you could imagine, a revolting human being. Barely a week goes by in which we don't learn of some new dimension to his awfulness. If there's any virtue he embodies or character flaw he has avoided, it's hard to think of what it might be.
Yeah but he got to the top of the ticket on the backs of these people, despite all his known flaws. Partisanship can explain his ability to hang around despite his conservative bona fides, but it can't explain his rise, which (ahem, "THEY'RE RAPISTS") was a foundational racial appeal. Also, the rich white guys I know are all heavily racist, but ultimately vote for who will lower their taxes, qed.
Do we know what industries they are typically in ? Someone who works in the oilsands in Alberta has a much higher income than me but they're also just waiting for another bust while the government seems to turn further and further away from their industry.
I haven't seen data that granular. Speaking from personal experience (not data, but instructive nonetheless) I know a retired Lear exec, a retired high up at GM, a retired Navy and commercial pilot, a man who used to own a wood milling firm, and a vascular surgeon who all support him. They are all rich and persistently so.