Even so devoted a bootlicker as Senator Lindsey Graham declared the debate a “disaster” for the ex-president.

Donald Trump is so feral and narcissistic, so unrestrained and so outside the norm of American politics, that he’s difficult to debate. It’s disorienting. Very few people have been able to stand up to him without being pulled into the muck. In the past, even when he lost debates on points, he dominated his opponents.

But on a Tuesday night in Philadelphia, Kamala Harris cracked the code.