Trump’s critics are actively exploring the path to impeachment or the invocation of the Twenty-fifth Amendment, which allows for the replacement of a President who is judged to be mentally unfit. During the past few months, I interviewed several dozen people about the prospects of cutting short Trump’s Presidency. I spoke to his friends and advisers; to lawmakers and attorneys who have conducted impeachments; to physicians and historians; and to current members of the Senate, the House, and the intelligence services. By any normal accounting, the chance of a Presidency ending ahead of schedule is remote. In two hundred and twenty-eight years, only one President has resigned; two have been impeached, though neither was ultimately removed from office; eight have died. But nothing about Trump is normal. Although some of my sources maintained that laws and politics protect the President to a degree that his critics underestimate, others argued that he has already set in motion a process of his undoing. All agree that Trump is unlike his predecessors in ways that intensify his political, legal, and personal risks. He is the first President with no prior experience in government or the military, the first to retain ownership of a business empire, and the oldest person ever to assume the Presidency…

Lance Dodes, a retired assistant clinical professor of psychiatry at Harvard Medical School, believes that, in this instance, the Goldwater rule is outweighed by another ethical commitment: a “duty to warn” others when he assesses that a person might harm them. Dodes told me, “Trump is going to face challenges from people who are not going to bend to his will. If you have a President who takes it as a personal attack on him, which he does, and flies into a paranoid rage, that’s how you start a war.”

Like many of his colleagues, Dodes speculates that Trump fits the description of someone with malignant narcissism, which is characterized by grandiosity, a need for admiration, sadism, and a tendency toward unrealistic fantasies. On February 13th, in a letter to the Times, Dodes and thirty-four other mental-health professionals wrote, “We fear that too much is at stake to be silent any longer.” In response, Allen Frances, a professor emeritus at Duke University Medical College, who wrote the section on narcissistic personality disorder in the Diagnostic and Statistical Manual of Mental Disorders—IV, sought to discourage the public diagnoses. Frances wrote, “He may be a world-class narcissist, but this doesn’t make him mentally ill, because he does not suffer from the distress and impairment required to diagnose mental disorder. . . . The antidote to a dystopic Trumpean dark age is political, not psychological.”

To some mental-health professionals, the debate over diagnoses and the Goldwater rule distracts from a larger point. “This issue is not whether Donald Trump is mentally ill but whether he’s dangerous,” James Gilligan, a professor of psychiatry at New York University, told attendees at a recent public meeting at Yale School of Medicine on the topic of Trump’s mental health.