For 23 days, President Joe Biden insisted on pushing forward with his reelection bid in the face of calls from Democratic lawmakers and donors for him to step aside. And then, almost on a dime, things changed. Early Saturday, Biden told senior aides it was “full steam ahead” for the campaign. But by later that evening, he had changed his mind following a long discussion with his two closest aides. Steve Ricchetti, who’s been with Biden since his days in the Senate, drove to see the president at his house on the Delaware shore on Friday. Mike Donilon arrived on...