Incapacity in the chief executive is not a new thing in American history. James Garfield spent half of his short presidency dying slowly from a gunshot wound. Richard Nixon’s condition in his final days was dire enough that his secretary of defense effectively cut him out of the nuclear chain of command. Woodrow Wilson’s stroke and his wife’s influence thereafter produced the immortal — if, of course, highly #problematic — complaint from one of Wilson’s senatorial critics that “we have a petticoat government! … Mrs. Wilson is president!”

What’s different about Donald Trump is that his inability to handle the weight and responsibility of his office is not something that crept up gradually, not something imposed by an assassin’s bullet or a stroke or a late-in-the-presidency crisis. Instead it’s been a defining feature of his administration from Day 1 — and indeed was obvious during the campaign that elected him.

This means that the president’s unfitness is not really a Harvey Weinstein-style “open secret,” an awful reality known to insiders but kept from hoi polloi, as The Atlantic’s James Fallows suggested this week amid the mania over Michael Wolff’s gonzo inside-the-White-House book. Indeed, it’s not any kind of secret: Even if it’s considered politically unwise for prominent Republicans to mention it, anyone who reads the papers (this one especially) knows that some combination of Trump’s personality and temperament and advancing age leave him constantly undone by the obligations of the presidency.

In a column early in his tempestuous first year, I suggested that this obvious fact potentially justified the invocation of the 25th Amendment, which permits a president’s cabinet in consultation with the legislative branch to remove him from the White House.