Donald Trump’s complaints about Gonzalo Curiel, the federal judge in a fraud case against Trump University, are nothing new. He’s been saying the same sort of thing since February, when he opined that the judge had “hostility.”

But last Thursday, Trump escalated his criticism to suggest that a “Mexican” — he describes many natural-born American citizens that way — could not be fair to him and conduct himself professionally as a judge. Judge Curiel’s Mexican descent makes him hostile, Trump says, even though the judge was born in Indiana.