There has been a significant change in voting behavior by income class between 2004 and 2016. Those with incomes under $30,000 in 2004 provided a 20% majority to the Democratic candidate; the Democratic share dropped to 16% in 2016. The loss of low income white votes in the the rust belt states cost her 70 electoral votes. Clinton did much better with higher income voters. Republicans got 15% of the votes from households with incomes between $100,00 - $200,000 in 2004. Households with incomes above $200 thousand in 2004 went Republican by 28%. In 2016 the Republican advantage in both of the high income groups fell dramatically to only 1%. There is greater parity between the two parties in the higher income groups. The drop in the Democratic share among low income Americans, which includes white and minority voters, goes a long way towards explaining Donald Trump's victory.
There is also a geographic interpretation of these results. The higher income voters are concentrated around the large cities in America. The Democratic Party has done much better with the richer and better educated voters in these cosmopolitan areas over this period. They did less will with lower income voters in these areas and Donald Trump got the great majority of votes from lower income Americans in rural areas. The Republican Party under Donald Trump is now a Populist Party but its fiscal policies in the key areas of taxation and government spending have a traditional Republican flavor. Trump will cut taxes for corporations and wealthy Americans while increasing government spending on infrastructure and the military. The resulting increase in the federal budget deficits will put the Democratic Party in a bind. It will have to choose between being the fiscally responsible party or to join the Trump bandwagon. In either case, is not clear that either party will be able to do much for low income Americans. Running budget deficits will provide a short term stimulus to the economy but it will lead to an increase in the value of the dollar and large trade deficits in the longer term.