It seems like there’s a self-selection problem: the non-white Trump voters are voters in Republican primaries, which probably makes them an unrepresentative sample of non-whites as a whole. In a general election match-up with Hillary Clinton or Bernie Sanders, common sense/opinion polling suggests that African-American and Hispanic voters without college degrees would vote for the non-Trump candidate by large margins compared to white voters without college degrees.
Also, you might want to check out this Upshot analysis: http://www.nytimes.com/2016/03/13/upshot/the-geography-of-trumpism.html. (The most relevant takeaway is that being white and not having a high school diploma is the variable most highly correlated with Trump support.)
Still, very interesting piece, I enjoyed it quite a bit.