DONALD TRUMP’S BIZARRE OBSESSION with IQ, or intelligence quotient, is fascinating. In 2016, presidential candidate Trump challenged a critic, Mayor Sadiq Khan of London: “Let’s do an IQ test,” as if intelligence testing were a board game, or an arm wrestling match.

Lately, Trump has been tossing around his crazy epithet “low IQ,” as in “very low-IQ individual Robert De Niro” or “low-IQ Mika Brzezinski.” I wonder if anyone other than De Niro’s mother has ever fretted about her son’s being Mensally challenged. He’s a great actor; does he need great board scores too?

Trump is not the first politician to ply these waters. In 1987, then-presidential candidate Joe Biden lashed out at a questioner, saying, “I think I have a much higher I.Q. than you do.” Biden then proceeded to make Trumpian, i.e. false, claims about finishing in the top half of his law school class.