Found via Nate Silver:

He writes of the “disaffecteds,” who are, “Older white voters with little education beyond high school, under enormous economic stress, the Disaffecteds surged to the Republican Party early in Mr. Obama’s first term.” (We’ve argued these “Disaffecteds” were driven by racial animus). However, there is an ongoing debate as to whether Trump supporters have a higher or lower income than other Republicans. This debate, while interesting, doesn’t get to the core of Trump support – family income isn’t a predictor of Trump support in any of our models. More importantly this narrative is difficult to square with the reality that though Blacks and Hispanics have significantly worse economic outcomes than whites, few have rushed to support Trump. In addition, we find that variables connected to economic anxiety do not predict Trump support after other factors are controlled for (a recent Washington Post analysis finds that racial concerns are stronger predictors of Trump support than economic ones). Rather, we find that what drives support for Trump is the mistaken belief that the government serves the interests of Blacks, rather than whites. Political scientist Brian McKenzie finds that, “whites who feel the Obama administration is looking out for the economic interests of blacks are more likely to express frustration with their own financial position.”

I don't know how much I trust a bar graph without error bars, but it's data for thought.