LET US assume, contrary to the known facts so far, that U.S. District Judge Gonzalo Curiel does harbor some bias against Donald Trump, the defendant in a class-action lawsuit brought to Judge Curiel’s Southern California courtroom by aggrieved former customers of the Trump University real estate school. Let us assume, further, and also contrary to known fact, that this bias even has something to do with Judge Curiel’s Mexican American heritage, as Mr. Trump venomously insists. The thing to do would be for Mr. Trump to file a motion with the court, urging the judge to recuse from the case and spelling out the reasons why. If the motion’s denied, he can appeal to a higher court.

The fact that Mr. Trump has not filed such a motion says a lot about his attitude toward the rule of law and stable political processes — more, in a sense, than his bigoted attacks on the judge themselves. When things don’t go his way, Mr. Trump’s first resort is not to use options for redress the system provides; it is, rather, to blame his problems on an enemy and whip up public hostility against him, in crude ethnic terms, if it seems advantageous. One implication of Mr. Trump’s words, that he is the one with a bias, against Americans of Latino heritage, is bad enough; possibly worse is the ominous signal his behavior sends about how a President Trump would deal with any sort of opposition he might encounter.

Having now staged this demagogic fit, Mr. Trump said Thursday in response to a query from the Wall Street Journal that he might just file a recusal motion after all. We shall see. He asserts that no honest judge could have failed to dismiss the lawsuit itself, the gist of which is that Trump University duped often vulnerable people into spending their savings on learning Mr. Trump’s overblown business “secrets.” His wild attacks on Judge Curiel, however, suggest that he’s actually a bit rattled by the course of the case so far, which has resulted in the disclosure of sketchy marketing methods carried on in his name.

To be sure, we have our own interest to disclose: It was The Post’s request for access to documents from the case that Judge Curiel granted May 27, sparking Mr. Trump’s latest tirade. However, we are far from the only ones to agree with Judge Curiel’s ruling that releasing the records would be in the public interest, given Mr. Trump’s status as the Republican near-nominee — and given the illumination of a potential president’s record they have, indeed, provided.

Based on the public record so far, Trump University, now defunct, looks like a scheme to enrich and aggrandize Mr. Trump by promising credulous people easy solutions to their very real problems — followed by Mr. Trump’s disavowal of responsibility toward those who lost out when the dreams he encouraged didn’t come true. Those who nevertheless sign up for his new political venture can’t say they weren’t warned.