James Comey, former FBI director, former deputy attorney general, former U.S. attorney for the Southern District of New York, is a friend of presidents and kings, an admired figure who presents himself as a voice of reason and morality, and a pillar of the Washington establishment — or, as the Mafia would put it, a made guy. Surely he would never do something so lawless and undemocratic as threaten the president of the United States, would he? That’s what Comey contends in response to charges that he was issuing a veiled threat to the president when he posted on his...