To do this, he draws on nationally representative survey data from the American National Election Studies and the Voter Study Group, two well-established surveys of voter attitudes and behavior. To measure views on immigration, the surveys ask respondents whether levels of immigration should be increased, decreased or left the same.
The surveys measure racial attitudes using a well-established battery of questions on “racial resentment.” Political scientists generally define this as something like “a moral feeling that blacks violate such traditional American values as individualism and self-reliance.” It’s measured via agreement with statements like, “It’s really a matter of some people not trying hard enough; if blacks would only try harder they could be just as well off as whites” and “Irish, Italians, Jewish and many other minorities overcame prejudice and worked their way up. Blacks should do the same without any special favors.”
The surveys also include a number of ways to measure what’s come to be known as “economic anxiety”: evaluations about the country’s economic health, as well as respondents' employment status and job market conditions in their communities, counties and states of residence.
Miller also controlled for a number of common economic and demographic variables, such as income, education, age, political party and gender. Respondents' race wasn’t included as a control because the study looked at the views of only white respondents.
Miller essentially ran a number of statistical tests to determine how white Americans' economic and racial attitudes correlated with their immigration beliefs: Does being unemployed make white voters more or less likely to support decreasing immigration? What about belief in the strength of the economy? As respondents' racial resentments increase, what does that do to their views on immigration?
All told, the analyses were “unequivocal that racial resentment is reliably the largest and most precise predictor of attitudes toward immigration,” Miller found. As the chart above shows, “racial resentment has the largest magnitude effect” on the odds that a white respondent will express a preference for less legal immigration. The effect of racial resentment has “nearly six times” the impact as a belief that the economy has gotten worse on respondents' propensity to favor less immigration.
The racial resentment questions ask only about attitudes toward black Americans. They don’t mention Hispanic immigrants at all. And yet, Miller found, white Americans' attitudes toward blacks were a powerful predictor of how they felt about immigration. “The familiar racial resentment toward African-Americans is part of a bigger syndrome in which ethnicity/race filters perspectives toward policy, more broadly,” he writes.
Miller cautions that the paper is still in its early stages and has not been peer-reviewed. But his findings do comport with much of the prior research on racial resentment and Trump support, and it makes sense that those attitudes would spill over into more general policy areas as well.
In the end, this should come as no surprise — the empirical case for restricting immigration is a poor one. Studies have consistently shown no link between immigrants and crime, for instance, and the net effect of immigration, legal or otherwise, on the economy tends to be positive, particularly in the long run.
In the end, Miller writes, “an ounce of racial resentment is worth a pound of economic anxiety.”