Speaking to raucous supporters at a faith rally at the John F. Kennedy Center for the Performing Arts in Washington, Mr. Trump brought the crowd to its feet by condemning news organizations.

“The fake media is trying to silence us,” Mr. Trump told the crowd at the concert hall, after returning to Washington briefly from his weekend getaway at his golf club in New Jersey. “But we will not let them. Because the people know the truth. The fake media tried to stop us from going to the White House. But I’m president and they’re not.”