Following Donald Trump’s election, the media tried to identify several indicators for why he won. Was it the opioid painkiller and heroin epidemic? Poor health outcomes? The economy?

A new paper by political scientists Brian Schaffner, Matthew MacWilliams, and Tatishe Nteta puts the blame back on the same factors people pointed to before the election: racism and sexism. And the research has a very telling chart to prove it, showing that voters’ measures of sexism and racism correlated much more closely with support for Trump than economic dissatisfaction after controlling for factors like partisanship and political ideology:

As the paper acknowledges, clearly economic dissatisfaction was one factor — and in an election in which Trump essentially won by just 80,000 votes in three states, maybe that, along with issues like the opioid epidemic and poor health outcomes, was enough to put Trump over the top. But the analysis also shows that a bulk of support for Trump — perhaps what made him a contender to begin with — came from beliefs rooted in racism and sexism.

Specifically, the researchers conclude that racism and sexism explain most of Trump’s enormous electoral advantage with non-college-educated white Americans, the group that arguably gave Trump the election. “We find that while economic dissatisfaction was part of the story, racism and sexism were much more important and can explain about two-thirds of the education gap among whites in the 2016 presidential vote,” the researchers write.

Now, the researchers didn’t measure just any kind of racism and sexism. For racism, they evaluated the extent that someone acknowledges and empathizes with racism — acting as a proxy measure for actual racist beliefs. (Research shows that these kinds of measures correlate with actual racism, which is tricky to measure in a more direct way since people will do what they can to avoid looking racist.) For sexism, they evaluated someone’s hostile sexism — which, through several questions, gauges hostile attitudes toward women. (For more on how hostile sexism is typically measured and compares with other types of sexism, read Libby Nelson’s explanation for Vox.)

To gauge these measures, the researchers looked specifically at national survey data from the online polling firm YouGov, taken during the last week of October.

YouGov’s data for likely voters had Hillary Clinton up by 3 points, which isn’t far from her final 2.1-point victory in the popular vote — suggesting that it’s fairly accurate.

Within this data, the researchers looked at respondents’ answers to various questions about the economy, racism, and sexism. The questions typically measured how much a respondent agreed with statements like, “I am angry that racism exists,” and, “Many women are actually seeking special favors, such as hiring policies that favor them over men, under the guise of asking for ‘equality.’” The researchers then matched responses to the scores shown in the chart above.

This isn’t the first study to produce these results. It’s been consistently demonstrated that racism and sexism played a big role in Trump’s Election Day victory. But knowing and proving the link between Trump and bigotry is crucial for anyone interested in defeating a candidate like him — or even Trump himself — in the future.

This isn’t the first study to link bigoted beliefs to support for Trump

By now, multiple analyses have found that support for Trump tightly correlates with racist and sexist beliefs.

Several polls found that Trump supporters were more likely to profess negative views of black people, Muslims, and Latinos, as well as concerns that immigrants threaten US values. One telling study, conducted by researchers at UC Santa Barbara and Stanford University shortly before the election, found that if people who strongly identified as white were told that nonwhite groups will outnumber white people in 2042, they became more likely to support Trump.

Another set of studies, conducted by researchers Carly Wayne, Nicholas Valentino, and Marzia Oceno, found that measures of benevolent sexism — meaning more traditional, chivalrous views of women and men’s proper roles in society — didn’t correlate closely with support for Trump. But measures of hostile sexism did, suggesting that sexism in support of Trump seems to be more about hostility toward women than old-fashioned views on gender roles.

None of this is too surprising — Trump, after all, ran a campaign in which he made explicit racist and sexist appeals. He characterized Mexican immigrants as criminals and “rapists.” He called for banning Muslims — an entire religious group — from the US. He said a US judge should recuse himself from a Trump University case due to his Mexican heritage. He referred to black and Latino people’s lives as hell, calling for police to adopt “stop and frisk” — a practice deemed unconstitutional in New York City because it was used in racist ways — to help protect “inner cities.” He suggested Fox News host Megyn Kelly was tough on him at a debate because she was menstruating. He was recorded on tape bragging he can sexually assault women (“grab ’em by the pussy”) because he’s a celebrity. And that’s far from all.

Why the racism and sexism behind Trump’s win matters

At some point, you might start to wonder why journalists keep writing about the link between Trump’s support and bigoted beliefs. The election is done. Do we really need to analyze what happened over and over again?

The point, at least for me, is not to demonize Trump voters. The point is to understand them in order to better grasp how they could vote for someone who ran a clearly bigoted campaign and who most voters agreed is unqualified for the nation’s highest office.

As Schaffner, MacWilliams, and Nteta write in their paper, there’s growing evidence that 2016 was unique — in that racism and sexism played a more powerful role than recent presidential elections. “Specifically, we find no statistically significant relationship between either the racism or sexism scales and favorability ratings of either [Republican candidate] John McCain or Mitt Romney,” they write. “However, the pattern is quite strong for favorability ratings of Donald Trump.”

The concern, then, is that this is the beginning of a modern trend in which politicians like Trump directly and explicitly play into people’s prejudices to win elections — and it works.

If that’s really what’s happening, it’s important for progressives and anyone interested in limiting the power of bigotry in US politics to know and demonstrate what’s going on. Studies like this put a bigger imperative on getting to the root of the problem and figuring out ways to reduce people’s racial or gendered biases.

To this end, the research also shows it’s possible to reach out to Trump voters — even those who are racist or sexist today — in an empathetic way without condoning their bigotries. The evidence suggests, in fact, that the best way to weaken people’s racial or other biases is through frank, empathetic dialogue. (Much more on that in my in-depth piece on the research.) Given that, the best approach to really combating racism and sexism may be empathy.

One study, for example, found that canvassing people’s homes and having a 10-minute, nonconfrontational conversation about transgender rights — in which people’s lived experiences were relayed so they could understand how prejudice feels personally — managed to reduce voters’ anti-transgender attitudes for at least three months. Perhaps a similar model could be adapted to reach out to people with racist, sexist, or other deplorable views, although this possibility needs more study.

But all of this involves a lot of legwork, outreach, and a kind of empathy that people may not be comfortable with in an era of highly polarized politics. Knowing what caused Trump’s win is crucial to gauging whether all of this work and effort is worth doing. And given the growing amount of research showing the major role of bigotry in Trump’s win, it certainly seems like the work and effort are needed.