In any event, why was this the FBI director’s call to make, rather than the president’s? If Trump is so confident about his lack of culpability in Russia’s cyberespionage that he was willing to run Comey’s “duty to correct” risk, what would have been the downside of informing the public that Trump was not under investigation — especially when any sensible person, on hearing what Comey did disclose, would assume that Trump was under investigation?

I don’t see how Trump could have handled Comey’s dismissal worse — no warning, conflicting explanations, talking him down in a meeting with Russian diplomats, savaging his reputation.

All that said, and as the former director learned painfully during the Clinton caper, the FBI and Justice Department should not make public statements about investigations unless and until they are prepared to file charges formally in court, where people get to see the evidence and have a chance to defend themselves. What possible good reason was there to alert the public that the Trump campaign was under investigation? Inevitably, that would induce the media to tell the world — incessantly — that Trump himself was under investigation.

Comey maintains, as he did in the July 2016 Clinton-e-mails press conference, that there is a “public interest” exception to the Justice Department rule against commenting on investigations. But public interest is the very reason for the no-comment rule. The point is to avoid smearing people who have not been charged with a crime. Such a smear happens only if the public is interested in the case.