He deemed BuzzFeed News “a failing pile of garbage,” mocked an inquiry about his tax returns — “Gee, I’ve never heard that one before” — and, in an unheard-of moment for a presidential news conference, shouted down questions from a CNN reporter, declaring, with some menace, “Not you.” “Your organization is terrible,” said President-elect Donald J. Trump, his voice rising as Jim Acosta of CNN tried to interject. “No, I’m not going to give you a question. I’m not going to give you a question.” “You,” the president-elect said, as Mr. Acosta and other stunned journalists looked on, “are fake...