Reuters A comprehensive Gallup report identifies the key qualities of those who support Donald Trump and finds they differ from those of other Republicans.

A detailed analysis published Thursday by Gallup’s Jonathan Rothwell finds evidence that disputes the popular “theory of Trump”: the idea that the success of GOP presidential nominee Donald Trump is predicated on harnessing grievances of the white working class. According to Rothwell, this picture misses the mark.

The Gallup study offers the most comprehensive statistical analysis of Donald Trump supporters to date, surveying more than 87,000 U.S. adults from July 8, 2015, through July 25, 2016, to identify the key qualities that characterize Trump’s backers.

Two main takeaways emerge: First, the political profile of those who favor Trump is vastly different from that of the traditional Republican voter. Second, the study finds that the aforementioned “theory of Trump” is largely false. Rothwell’s statistical analysis points instead to different significant factors that unify Trump supporters: They tend to live in homogenized, racially isolated pockets of the United States and exhibit lower levels of education.

The political profile of the Trump supporter differs from the average Republican ― Trump supporters are significantly further to the right on the ideological scale, the paper finds. They tend to be older, are more likely to be white (non-Hispanic) males, less likely to identify as LGBTQ, and far less likely to hold a bachelor’s degree or have any form of higher education.

Compared to the average Republican, they are also more likely to be a veteran or family member of a veteran, more likely to work in a blue-collar occupation, and more likely to be Christian and report that religion is “important to them.” They are slightly less likely to be unemployed and more likely to be self-employed, more likely to be retired, have higher mortality rates for middle-aged whites (a measure for standard of living), and are significantly more likely than other Republicans to oppose trade and immigration.

Johnny Louis via Getty Images Trump at a campaign rally.

Notably, however, there was no statistically significant difference between the median household incomes for the zip codes that Trump supporters and non-supporters live in.

This runs contrary to the theory that Trump appeals to the economic grievances of the white working class. The data suggests that those who view Trump favorably are not experiencing anomalous levels of economic distress along standard measures such as income and employment.

Individuals who live in zip codes with disproportionately high shares of white residents, however, are far more likely than others to view Trump favorably. This correlation is further supported by a related finding: Those farther away from the Mexican border are more likely to view Trump favorably.

This may not be altogether surprising in light of Trump’s penchant for espousing racially and culturally divisive rhetoric. It provides a powerful example of “contact” or “intergroup” theory, which holds that limited interactions with racial and ethnic outgroups may contribute to prejudicial stereotypes against them.

Level of education also proves to be an extremely powerful indicator of support for the GOP nominee. A “one standard deviation increase” in the share of those above the age of 25 with a bachelor’s degree predicts “a 3 to 5 point decrease in support for Trump.”

Trump supporters, in other words, are united not merely by working class grievances, but more powerfully by racial and cultural isolationism.

“Trump is giving his supporters a misleading account of their ills,” Rothwell said. “He says they are suffering because of globalization … Because of immigration and a diversifying country, but I can’t find any evidence of that [being the case].”