Go back to his initial staffing of senior posts and recall how shoddy the vetting process was. Also notice two prominent classes of recruits: people who had profoundly questionable preparation for the jobs that he nonetheless gave them (Ben Carson, Betsy DeVos, Stephen Miller, Javanka) and genuine professionals who wagered that their skills would be critically necessary — and thus highly valued — and that Trump would surely rise to the established codes and expected conduct of his office.

Now look at how many of those professionals (James Mattis, H.R. McMaster, Gary Cohn, Dan Coats) are gone. And tell me whether Trump has ever had the epiphany that the presidency is, in fact, a profession.

A crisis of professionalism defines his administration, in which backstabbing is the new glad-handing, firings are cruel, exits are ugly, the turnover is jaw-dropping, the number of unfilled positions is mind-boggling, and many officials have titles that are prefaced with “acting” — a modifier with multiple meanings in this case.

Trump slyly markets his anti-professionalism as anti-elitism and a rejection of staid, cautious thinking. But it’s really his way of excusing his ignorance, costuming his incompetence and greenlighting his hooliganism.

He rejects professionalism because it tempers self-promotion and forbids such grandiose claims as his insistence that he knows more about the Islamic State than any military general. “I alone can fix it,” he boasted at the Republican convention in 2016. “I’m the only one that matters,” he said the following year when dismissing any concerns about job vacancies. A true professional would have trouble uttering those words. They roll easily off a true huckster’s tongue.

Professionalism involves credentials, benchmarks, all sorts of yardsticks by which a person can be judged, sometimes unkindly. Trump wants only affirmation. And professionalism is a reality-based enterprise. Trump prefers fiction: The Ukraine call was “perfect.” “Read the transcript” because it exonerates him. His critics are partisan hacks. He’s the target of an interminable “witch hunt.”

But Robert Mueller was no more hunting witches than Bill Taylor is an agent of the deep state. In fact Mueller stands out as a consummate professional, so much so that he politically neutered himself, and “deep state” is Trump’s deeply cynical pejorative for “seasoned professionals.”