55% of his supporters are white and working class, according to a new study from the Public Religion Research Institute (PRRI) and the Brookings Institution. Using the report as a springboard, opinion columnist William A. Galston writes in the Wall Street Journal that Trump is the “staunchest champion of the white working class that American politics has seen in decades.”

As anyone who’s acquainted with his campaign knows, the Republican presidential frontrunner is tapping into Americans’ fear of immigrants. According to the PRRI/Brookings study, 69% of Trump voters say immigration is a very important issue to them. Only around 50% of Republicans supporting other candidates say immigration is important.

The Trump campaign did not immediately respond to requests for comment on the PRRI/Brookings study.

The racial aspect of Trump’s support goes deeper, says Galston:

The outlook of core Trump supporters also reflects an identity shaped by class and race. These voters are least likely to say that government is looking out for the interests of the middle class or of white men, and the most likely to affirm that there is discrimination against these groups. Fifty-three percent believe that police officers generally treat blacks and other minorities the same as whites.

In many ways, Trump’s type of campaign hasn’t been seen since 1968, when George Wallace stormed the gates of American politics on the back of his segregationist platform. Writing in Slate, Jamelle Bouie has noted the similarities between the two:

Trump doesn’t reflect Wallace in his biography. The similarity is in his style and approach. Wallace was a politician for people who felt powerless, regardless of the reality. First as a fighter for segregation in the face of civil rights victories and later as a voice for “law and order” against the specter of crime and disorder, Wallace harnessed the fear and anger of millions of Americans with a pledge, in a sense, to take back their country.