And, of course, Comey had no idea whether those emails, or anything else significant, were on Weiner’s computer. What he should have done was start an investigation and then see what it turned up, without making those actions public. That’s what the F.B.I. normally does, and what it did in the case of the Trump campaign and Russia.

Comey believes, The Times reported in its investigation of the affair, that the F.B.I. should avoid needlessly casting public suspicion on people. Except if those people, apparently, are Hillary Clinton or her aides, friends and associates.

Comey tried to wriggle out of the charge that he had publicly disclosed the reopening of the Clinton investigation, saying he had sent a “private” letter to the lawmakers about it. But that letter became public instantly, as Comey had to know it would.

Comey said he and his aides debated whether to inform Congress about the search warrant, with an election 11 days away. Contemplating the possibility of influencing that vote, Comey said he thought at the time, “Lordy, that would be really bad.”

But he thought that not revealing the new investigation would be “catastrophic.” It’s not clear what catastrophe he had in mind, other than Clinton being elected while the F.B.I. was still looking at the emails, which they miraculously managed to finish doing two days before the vote.

So Comey chose “lordy, that would be bad” over “catastrophic.” He didn’t offer much insight into the difference, other than catastrophic sure sounds worse.

The Times’s investigation of Comey’s handling of the email investigation found that he did not deliberately act out of partisanship. But he certainly handled the Clinton and Trump investigations in different ways that had profound partisan impacts. But even if he wasn’t motivated by partisanship, he showed incredibly bad judgment. For an F.B.I. director, that’s disturbing, too.