Comparing economics between states and even locations vs. how they voted I don't think that's accurate. https://en.wikipedia.org/wiki/Simpson%27s_paradox makes this stuff harder to calculate than you might think.

Look at VA income: https://en.wikipedia.org/wiki/Virginia_locations_by_per_capi... vs. http://www.politico.com/2016-election/results/map/president/... Poor areas are vastly more likely to vote republican.

Arlington county median income $101,000: 77.0% Clinton vs 16.9% trump.

Lee County $50,014 income: 17.4% Clinton vs. 80.6% trump

Trump was very popular with the rural uneducated and thus poor.

PS: DC get's a bad rap, but once again top 5 income compared to state and was only beaten by other heavily democratic states. https://en.wikipedia.org/wiki/List_of_U.S._states_by_income 4% of DC voted for Trump.