In the last week, Republican presidential candidate Donald Trump came under fire for his response to the news that former Ku Klux Klan leader David Duke had publicly supported Trump’s campaign, joining a number of white supremacist groups who have rallied behind him.

But then Trump had only solidified his position as the Republican front-runner in the race for the White House with convincing victories on Super Tuesday, even in states like Vermont and Massachusetts.

What  explains Trump’s astounding success among the Republican electorate, despite his controversial statements about topics related to race and immigration?  A number of political scientists have found that those statements might actually be a key reason for his success. Support for Trump is highest among whites who express ethnocentric viewpoints, score high on measures of authoritarianism, identify strongly as white, and who express negative views of racial minorities.

Now a new poll that we conducted adds another dimension. In particular, we directly measured Americans’ fear of the demographic change that is projected to make the United States a majority-minority nation by the year 2043. Recent work has found that white Americans, once told about this impending demographic shift, are more likely to identify with the Republican Party, to express conservative policy positions, and view themselves as conservatives.

Views of this demographic shift matter in the Republican primary, too.

Our poll was fielded among registered Massachusetts voters the week before Super Tuesday. We asked respondents this question, which was previously fielded by the Pew Research Center:

According to the U.S. Census Department, by 2043 African Americans, Latinos, and people of Asian descent will make up a majority of the population. In general, do you think that this is a good thing or bad thing for the nation?

Of the respondents who expressed an interest in voting in the Republican primary, just 6 percent saw the ascent of the minority population as a good thing, while 45 percent said it was a bad thing, and 49 percent said neither. Trump won the support of more than 60 percent of those who responded “bad thing” to this question.

The relationship between responses this question and Trump support persists even after accounting for a respondent’s ideological affiliation, educational experiences, age and gender. Individuals who think the increase in the minority population is a bad thing are 20 percentage points more likely to support Trump than those who responded “good thing” or “neither.”

Of course, our data is derived only from Massachusetts, which is thought to be unrepresentative given the ideological leanings of its citizens.  However, Massachusetts also has a long history of racial turmoil, including the violent reactions of white residents to busing plans, the reaction of the Boston Police to the false allegations of Charles Stuart, and the national furor that resulted from the arrest of Henry Louis Gates.

So perhaps it is not surprising then that in Massachusetts, as in the country more broadly, support for Trump depends in part on an apparent tension between the growing minority population and the white Americans who look unfavorably on an increasingly diverse nation.

Tatishe Nteta and Brian Schaffner are professors in the Department of Political Science at the University of Massachusetts-Amherst.