Officials at the D.O.J. tried to convince the F.B.I. that all Comey had promised Congress was that he would take a look at new information, that he risked creating another misimpression by sending a letter, that doing this so close to an election was insanity, and that “the overwhelming odds are that this will amount to nothing,” as one former official puts it.

One argument that the F.B.I gave in response was that now that the circle had become much bigger, including agents in New York, the probability of a leak was high and would only increase once the request for the warrant was filed. “Yes, it was absolutely explicit that one reason for the letter was that the agents in New York would leak it,” says a Justice Department source. “That is a crappy reason. You can’t manage your people? And a leak would have been better than what happened.” (In fact, on the morning of November 4, Giuliani returned to Fox & Friends, to gloat, “Did I hear about it? You’re darn right I heard about it.” Later that day, he tweeted, “I still challenge someone to produce proof of my direct involvement w @fbi.”)

But, multiple sources say, the Justice Department never ordered Comey not to send the letter, and neither Lynch nor Yates personally called Comey. Instead, staff called over to the F.B.I. A source says, “I do know that [Lynch] never spoke directly to Comey, and she didn’t allow the D.A.G. to speak to him. . . . In his position, I would have understood this as permission to do what I wanted.” He adds, “Before something this consequential would occur, you would at least want the A.G. to look Jim Comey in the eye and say, ‘Do not do it.’ ”

On November 6, two days before the election, Comey informed Congress that the F.B.I. had seen the e-mails and that the bureau had not changed its conclusion that Clinton should not face charges over her handling of classified information.

The result was predictable: Republicans again insisted the game must be rigged, and Democrats couldn’t believe Co­mey had re-ignited the issue on the eve of the election. Even the Justice Department joined the blame game, leaking a story to The New York Times in which officials claimed they’d done practically everything possible to dissuade Comey from sending the letter.

One source disagrees, saying: “As immense as my criticism is for Comey, it is greater for the A.G. and the D.A.G. If they had said, ‘You can’t send that letter,’ he wouldn’t have done it.” “They claim they couldn’t have stopped it, but that is bullshit,” says a former prosecutor, who says that, even today, “they don’t get it, don’t admit responsibility. They say, ‘We couldn’t do anything—you know what he’s like.’ ”

Another observer, who is deeply familiar with the Justice Department, adds, “I know exactly why they didn’t call themselves! They were all thinking, Hillary is going to win. If you could look back and say this would swing it to Donald Trump, you would do anything to stop it, but they were worried that, if they told Comey not to do it, that would leak [from the F.B.I.], and they would be accused of interfering.” (Lynch, Comey, and Yates declined to comment for this article.)

“People say [Lynch] should have ordered him not to do it. I get with 20/20 hindsight why people feel that way,” a Justice Department source responds. “But it was not a situation where [Comey] said, ‘We need to talk.’ It was presented as ‘The director intends to do this. He has an obligation to correct a misimpression that Congress has as a result of his testimony.’ It was portrayed as ‘His reputation is on the line.’ When it is framed that way, as ‘I need to do this or Congress will be misled,’ all of the A.G.’s options are bad. Either he obeys, and she is accused of obstructing justice. Or he disobeys and does it anyway. Or he resigns. All of these are terrible. He put her in an impossible situation.”