For the record, Judge Gonzalo Curiel isn’t Mexican. Photo: Spencer Platt/Getty Images

Republican presidential nominee Donald Trump escalated his attacks on U.S. District Judge Gonzalo Curiel on Thursday, telling The Wall Street Journal that Curiel, who is presiding over two lawsuits against Trump University, had “an absolute conflict” in the case on account of his “Mexican heritage.”

Recalling his comments from last week, in which he called Curiel “a hater of Donald Trump” and “totally biased,” Trump alleged that the judge could not handle the case impartially due to his Mexican ancestry and his membership in an association of Latino lawyers.

In Trump’s formulation, Curiel’s ethnicity is relevant because, as a Latino, he presumably isn’t fond of the candidate’s stance on illegal immigration and his promise to build a wall along the Mexican border. “I’m building a wall,” he said. “It’s an inherent conflict of interest.” Trump added that he might file a motion asking the case, which he believes any other judge would have thrown out, to be reassigned.

Curiel, an Obama appointee, is not actually Mexican — he was born in Indiana to Mexican immigrant parents. In keeping with the code of conduct for federal judges, he declined to respond to Trump’s comments when the Journal contacted his office.

Trump’s campaign has attempted to make hay out of Curiel’s membership in the La Raza Lawyers Association, an association of Latinos working in the legal profession in California.

“This is an organization that has been out there organizing anti-Trump protesters with the Mexican flags — they are pushing it,” Trump spokesperson Katrina Pierson claimed in a CNN appearance on Monday. “The signs have been very apparent. And so Mr. Trump is just stating the obvious.”

As Vox notes, there is no evidence linking the La Raza Lawyers Association to any anti-Trump agitation. Pierson may have confused (or deliberately conflated) the association with the National Council of La Raza, a Hispanic advocacy organization based in Washington that has criticized Trump’s inflammatory rhetoric and extreme positions on immigration and the border. Neither Curiel nor the association to which he belongs appear to have any direct affiliation with the National Council of La Raza.

Comments such as the ones Trump made today could get in the way of his campaign’s outreach to Latino voters, whose support Trump has insisted he will win in November despite polling consistently terribly with this demographic.

In fact, Trump’s alienation of the Latin-American community has gotten so bad that it’s making Republican leaders very nervous: Senate Majority Leader Mitch McConnell voiced fears in a CNN interview on Thursday that his party’s nominee would drive Latinos away from the party for good, much as 1964 GOP nominee Barry Goldwater destroyed the party’s standing with African-Americans with his opposition to the Civil Rights Act.

Speaker of the House Paul Ryan, meanwhile, is probably wishing he had endorsed Trump at a different point in the news cycle.