District Attorney Alvin Bragg’s declaration that he does not oppose a postponement of President Trump’s sentencing in the New York criminal trial is a head scratcher. It was Mr. Bragg who persuaded a Gotham jury to convict the 45th president on 34 counts for falsification of business records in connection with payments to an adult film star, Stormy Daniels. The case was widely seen as flimsy, yet once launched it sailed to nearly three dozen “guilty” verdicts.