Hillary Clinton attends a rally in Scranton, Pa. in August. (Photo by Melina Mara/The Washington Post)

During a fundraiser on Friday, Hillary Clinton repeated a theory about Donald Trump's supporters that has become widespread in the media -- a theory that divides them into two groups. Some of his supporters are motivated by bigotry and prejudice, Clinton said. The Democratic presidential nominee put this group into what she called "the basket of deplorables." Other supporters are motivated by broader frustrations about politics and the economy, Clinton added.

"That other basket of people are people who feel that the government has let them down, the economy has let them down, nobody cares about them, nobody worries about what happens to their lives and their futures, and they’re just desperate for change," she said.

Many pundits look at Trump's voters in a similar way, implicitly dividing them into those motivated by economic concerns and those motivated by racial anxieties, and there has been a fierce debate over which group has been more important to Trump's unanticipated success.

Yet the data suggest this is a false dichotomy. Many of Trump's supporters have both motivations, polls suggest.

In a poll earlier this year, The Washington Post and ABC News found that Republicans and Republican-leaning independent voters who supported Trump in the primary could be divided into not two, but four baskets of roughly equal size based on their economic and racial anxieties:

Only 26 percent of Trump's supporters said that they were not struggling economically or in the lower class, but that it was a bigger problem that whites were losing out to African Americans and Hispanics than vice versa -- the group that most closely corresponds to how Clinton described the 'basket of deplorables.' Another 20 percent said they did not think it was a problem that whites were losing out, but they did put themselves in the lower class or said they were struggling economically.

Twenty-five percent of Trump's supporters said both that whites were losing out and reported economic distress. Finally, 24 percent said neither that they had financial problems nor that whites were losing out.

By contrast, Republicans and independents who supported primary candidates other than Trump were much less likely to say either that they were in economic straits or that whites were losing out to other racial and ethnic groups.

Other polls also show the difficulty of neatly separating Trump's voters by their motivations. As The Washington Post's Jeff Guo showed in an analysis of data from the American National Election Studies, white Republicans who are more racially resentful -- those who think African Americans aren't trying hard enough or are getting more than they deserve, for example -- also have more negative views of the economy.

That many of the Republican nominee's supporters report both economic and racial concerns is not surprising. On the one hand, social scientists have long argued that economic distress can motivate racial prejudice. One group of German economists has found that since 1870, European far-right parties have typically won more votes following financial crises. Notre Dame sociologist Rory McVeigh has written that declines in agricultural and manufacturing employment helped white-supremacists groups expand in the United States.

A pair of psychologists at New York University recently showed how economic distress might make people more aware of race. In an experiment with photographs of racially ambiguous faces, people who had been primed to think about "scarcity" -- the economic concept for resources in limited supply, like money and food -- were more likely to see the faces as black.

On the other hand, racial animosity might influence how people see the economy. Whatever their actual circumstances, people who resent other racial groups might feel that they are falling behind if they believe that those other groups are making progress. One recent experiment at Stanford University found that white subjects were more likely to support the tea party when told that average white incomes were declining relative to average incomes for other groups.

Given all these connections between racial and economic anxiety, the debate over these two sources of Trump's support might seem arcane. Clinton's comments, though, demonstrate why it matters: Some Democrats and Republicans who are opposed to Trump might have more sympathy for Trump's voters if they are in dire economic straits.

"Those are people we have to understand and empathize with as well," Clinton said Friday. She did not make a similar remark about the people in the other basket. "Some of those folks, they are irredeemable," she said.

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