Donald Trump’s presidential campaign acknowledged in an internal memo that former FBI Director James Comey’s 11th hour decision to reopen an inquiry into Hillary Clinton’s use of private email helped shift the results.

Reported in Joshua Green’s new book Devil’s Bargain, the memo gives credence to an argument long espoused by Clinton world that Comey’s announcement propelled Trump to victory.

The wording itself isn’t that explicit. But it constitutes primary evidence documentation in general support of this theory.

The memo was authored by some of Trump’s pollsters and data gurus just five days before the vote. Days earlier, Comey had reopened his investigation after FBI agents found additional emails on a laptop belonged Anthony Weiner, the now estranged husband of Clinton’s longtime aide Huma Abedin. While polling began to swing towards Trump, virtually all prognosticators still had Clinton heading for a comfortable win on November 8. On the Trump campaign, however, Green writes that “it was suddenly clear” that the investigation “was roiling the electorate.”

“The last few days have proven to be pivotal in the minds of voters with the recent revelations in reopening the investigation of Secretary Clinton,” the memo read, according to Green. “Early polling numbers show declining support for Clinton, shifting in favor of Mr. Trump.”

It added: “This may have a fundamental impact on the results.”

Trump and his aides have long disputed that idea that Comey cost Clinton a win, calling those who insist otherwise sore losers. They also have noted, correctly, that Clinton paid scant attention to several of the critical Rust Belt states that she ended up losing.

Two senior Trump campaign veterans, who spoke to The Daily Beast on the condition of anonymity in order to speak freely, acknowledged on Monday night that the Comey letter helped. They maintained, however, that Team Trump had already begun seeing “the numbers moving [in our direction] before the Comey” letter was sent.

“We literally saw the [internal poll] numbers move in [and right after] that third [presidential] debate in real time,” especially with Trump’s answer on conservative Supreme Court justices that “galvanized Republican numbers” and “lit the spark,” one former Trump campaign official said.

“[Many in the campaign were] pessimistic but some in the [top] ranks saw glimmers of hope even before the Comey letter hit,” the second Trump 2016 vet said, still conceding however that it is very “difficult to write the history of [Trump’s] win without mentioning Comey.”

Green also reports that Trump's internal numbers had him gaining momentum before the Comey letter, which then provided a “sharply upward” turn “in every state.” By the time they published the five-day-out memo, aides worried that the campaign was already leveling off.

Elsewhere in his book, Green makes clear just how surprising the final win was to Trump’s team. In the close of the campaign, he reports, chief strategist Steve Bannon had devised a scorched-earth approach to the close of the campaign that was premised on a Clinton victory.

“Our backup strategy,” he said of Clinton, according to Green, “is to fuck her up so bad that she can’t govern. If she gets 43 percent of the vote, she can’t claim a mandate.”

Later, Bannon added: “My goal is that by November 8, when you hear her name, you’re gonna throw up.”

Green’s book, which was obtained by The Daily Beast at a Washington D.C. bookstore, is one of the more detailed accounts of Donald Trump’s political rise, Bannon's broader ambitions, and the rough-and-tumble 2016 presidential campaign.

In it, he reveals that the presidential run nearly didn’t happen. Trump was tantalizing close instead to launching a bid for governor of New York as a Republican in 2014, under the assumption that a surprise victory would have catapulted him to the presidency. He spoke with GOP lawmakers and party officials and had polling commissioned from his future campaign manager, Kellyanne Conway.

Trump would likely have been destroyed. Conway’s polling had him down 35 points to Gov. Andrew Cuomo (D-N.Y.). But she chose not show him that number and, instead, talked up his chances as a celebrity politician in the vein of the Kennedys. Much to the chagrin of his aides, Trump was nearly convinced. He travelled the state and tried to get the other potential candidates to clear the field.

Roger Stone, a longtime Trump confidant, told Green that Conway’s analysis was “an enormous crock of shit.” He also called David Bossie, a long-serving conservative operative who was advising Trump at the time, a “major douchebag devoid of any political talent—and that’s on the record.”

Ultimately, Trump opted to skip the gubernatorial campaign to focus on the 2016 race.

The rest, yada yada, is history.