That would suffice in almost any other circumstance. A judge’s orders and rulings are in the public record; those writings can speak for themselves. But Trump is more than the typical scorned defendant. His accusations against Curiel’s integrity are serious, the platform from which he hurls them is massive, and he seems unwilling to relent in making them. A growing chorus of American legal scholars from the left, right, and beyond says his remarks threaten the rule of law.

The real-estate businessman also has another problem: There’s no evidence whatsoever in the public record to support Trump’s claims about Curiel.

We’ll start at the beginning. Curiel is presiding over two separate class-action lawsuits about Trump University. One of them, Low v. Trump University, was filed in April 2010 under the name Markaeff v. Trump University. The other, Cohen v. Trump, was filed in October 2013. (A third case brought by New York Attorney General Eric Schneiderman in 2013 is also under way in that state.) Trump is named as a defendant in both cases.

The plaintiffs in Low and Cohen portray Trump University as a basically fraudulent endeavor, one that promised Trump’s secrets to real-estate success but instead dispensed generic advice for tens of thousands of dollars. They’ve amassed a collection of evidence and testimony that seems to support their claims. Trump strongly denies the allegations and often cities numerous positive testimonials the seminars received from former customers of Trump University.

In his public remarks, Trump appears to make no distinction between Low and Cohen. But there are crucial differences between the two civil class-action lawsuits. The Low plaintiffs sued Trump University and Trump himself under various consumer-protection laws in California, Florida, and New York—a relatively standard class-action lawsuit.

Cohen, on the other hand, targets Trump through a provision of the federal Racketeer Influenced and Corrupt Organizations Act, more commonly known as the RICO Act—the same statute federal prosecutors use to bring down mob bosses. In essence, Low accuses Trump University of engaging in fraudulent business practices, while Cohen frames Trump University itself as a criminal enterprise with Trump as the orchestrator of a racketeering scheme.

As you can imagine, Trump strongly opposes that characterization. In a motion for summary judgment in Cohen filed in March, he condemned the “pervasive abuse of civil RICO” that he says the case represents. “Indeed, if this case is allowed to proceed, it would represent an unprecedented and unprincipled expansion of civil RICO and transform virtually every alleged violation of consumer protection laws into a civil RICO claim,” Trump argued.

Beyond Curiel’s ethnicity, Trump’s most specific grievance against the judge is that he wrongly denied summary judgment in Trump’s favor. This assertion is only partially accurate. Trump asked Curiel for it separately in each case, filing the motion for Low in February 2015 and for Cohen in March 2016. The Cohen motion is still pending, with a hearing scheduled for July 18. Trump’s frustration likely springs from Curiel’s ruling against him last November on most of the Low summary-judgment motion.