Yeah, people need to remember that we already have studies that show that racial bias in America (people who feel that blacks get too much and that whites don't get enough) was the strongest predictor of people switching their vote from Obama to Trump.Racial resentment was a better predictor of Trump support than Romney support. And was an explanatory variable in voting patterns based on education among whites.
Racial resentment also leads to skewed view of unemployment and the economy. I.e. higher racial animus among whites was correlated with perception of increasing unemployment despite it falling in 2012. Or as Michael Tesler put in his headline: Economic anxiety isn't driving racial resentment. Racial resentment is driving economic anxiety.
Data shows an increased association between the Democratic candidate and aiding black people.
Barack Obama won Indiana in 2008. He visited it 5 times in his first term. He helped bring unemployment there down. And it voted for Rmoney.
I'm not sure why it's astonishing to people that:
1) voting for Obama doesn't mean you can't be racist.
2) this campaign was more explicitly racially driven than past.
3) President Obama, while an inherent symbol of black America did not talk about it much in his first term or prior; and when he did there was backlash like that experienced in his second term.
4) the general landscape of racial issues in politics has changed from 2012 and 2008 and 2004 and so on.
5) the prospect of large numbers of people being something you consider bad, in this case racist, does not make it implausible.
This doesn't mean Clinton ran a good campaign, I mean it actually amounts to a critique in that she clearly talked to much and too explicitly about racial issues. And certain white people did not like that very much.
We already knew the cause of why people switched their votes.