More than a year after President Donald Trump won the election, there are still some questions about what drove him to victory: Was it genuine anxiety about the state of the economy? Or was it racism and racial resentment?

Over at the Washington Post, researchers Matthew Fowler, Vladimir Medenica, and Cathy Cohen have published the results of a new survey on these questions, with a focus on the 41 percent of white millennials who voted for Trump and the sense of “white vulnerability” that motivated them. The conclusion is very clear:

Contrary to what some have suggested, white millennial Trump voters were not in more economically precarious situations than non-Trump voters. Fully 86 percent of them reported being employed, a rate similar to non-Trump voters; and they were 14 percent less likely to be low income than white voters who did not support Trump. Employment and income were not significantly related to that sense of white vulnerability. So what was? Racial resentment. Even when controlling for partisanship, ideology, region and a host of other factors, white millennials fit Michael Tesler’s analysis, explored here. As he put it, economic anxiety isn’t driving racial resentment; rather, racial resentment is driving economic anxiety. We found, as he has in a larger population, that racial resentment is the biggest predictor of white vulnerability among white millennials. Economic variables like education, income and employment made a negligible difference.

The survey looked at millennials because they will be the largest share of the voting-eligible population in 2018, so they’re an important bellwether for future trends. (At the same time, most millennials backed Hillary Clinton in 2016, not Trump.)

To anyone who’s been following the research on this, the findings should come as little surprise. There have now been numerous studies that found support for Trump is closely linked to racial resentment, defined by Fowler, Medenica, and Cohen as “a moral feeling that blacks violate such traditional American values as individualism and self-reliance.”

This is crucial to understanding both Trump’s rise and how to overcome Trump. As a presidential candidate, Trump made all sorts of racist comments — suggesting that Mexican immigrants are criminals and rapists, proposing a ban on all Muslims entering the US, saying a US judge should recuse himself from a case simply because of his Mexican heritage, and deploying dog whistles about “law and order.”

As president, Trump equated a group of neo-Nazis, white supremacists, and white nationalists who descended onto Charlottesville, Virginia, with the anti-racism protesters who stood against bigotry. His administration has also pursued policies that will disproportionately hurt minority groups, including his travel ban, immigration restrictions, “tough on crime” policies, and potential voting restrictions.

The studies suggest that these kinds of comments and actions are not just incidental to Trump; they are at the core of his political success. If Democrats want to defeat him, they will need to overcome that racial resentment.

The latest findings are backed by many other studies

This is not a one-off finding. At this point, the evidence that Trump’s rise was driven by racism and racial resentment is fairly stacked.

One paper, published in January by political scientists Brian Schaffner, Matthew MacWilliams, and Tatishe Nteta, found 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.

Another study, conducted by researchers Brenda Major, Alison Blodorn, and Gregory Major Blascovich 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.

And a study, published in November by researchers Matthew Luttig, Christopher Federico, and Howard Lavine, found that Trump supporters were much more likely to change their views on housing policy based on race. In this study, respondents were randomly assigned “a subtle image of either a black or a white man.” Then, they were asked about views on housing policy.

The researchers found that Trump supporters were much more likely to be impacted by the image of a black man. After the exposure, they were not only less supportive of housing assistance programs, but they also expressed higher levels of anger that some people receive government assistance and were more likely to say that individuals who receive assistance are to blame for their situation.

In contrast, favorability toward Hillary Clinton did not significantly change respondents’ views on any of these issues when primed with racial cues.

“These findings indicate that responses to the racial cue varied as a function of feelings about Donald Trump — but not feelings about Hillary Clinton — during the 2016 presidential election,” the researchers concluded.

There is also a lot of other research showing that people’s racial attitudes can change their views on politics and policy, as my colleague Dylan Matthews as well as researchers Sean McElwee and Jason McDaniel previously explained for Vox.

Simply put, racial attitudes were a big driver behind Trump’s election — just as they long have been for general beliefs about politics and policy.

To confront Trump, opponents will need to confront racism

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 over. 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 what motivated them to 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 wrote in their paper, there’s growing evidence that 2016 was unique — in that racism and sexism played a more powerful role than in recent presidential elections. “Specifically, we find no statistically significant relationship between either the racism or sexism scales and favorability ratings of either [previous Republican candidates] John McCain or Mitt Romney,” they wrote. “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 to people’s prejudices to win elections — and it works. This is in many ways an outgrowth of the Southern Strategy and tactics that play into people’s racism, like dog whistles — only it’s more explicit in its bigotry.

If that’s really what’s happening, it’s important for 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 biases.

To this end, the research also shows it’s possible to reach out to Trump voters — even those who are racist today — in an empathetic way without condoning their prejudice. 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 strongest approach to really combating racism and racial resentment 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-trans 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 the growing body of evidence suggests that it truly is.