It was wheels-up at Joint Base Andrews as Peter Baker, the chief White House correspondent for The New York Times, settled into the Air Force One press cabin on May 19 at the start of a presidential flight to Riyadh, Saudi Arabia. Then his cell phone rang with a heads-up from his boss, Washington-bureau chief Elisabeth Bumiller, that the paper was about to break a big story: Donald Trump had denounced James Comey—whom he had just fired as F.B.I. director—as a “nut job” during a meeting with Russian officials in the Oval Office. He had also told the Russians that Comey’s ouster relieved “great pressure” on him just as the F.B.I. investigation of the Trump campaign and contacts with Russian officials seemed to be gathering momentum.