Donald J. Trump has made his revisionist account of the Capitol attack the foundation of this campaign, even when there is little political advantage.When a moderator asked Donald J. Trump about Jan. 6, 2021, at the presidential debate, the former president slipped immediately into a now-familiar revisionist history of the attack on the U.S. Capitol. He falsely claimed that he had nothing to do with the assault, blaming it on former House Speaker Nancy Pelosi and the police officers who protected the building that day against a mob of his supporters. But then Mr. Trump made a brief but telling...