After President Obama’s mediocre first debate performance against Mitt Romney in 2012, he reportedly told advisors “I just don’t know if I can do this,” when they urged him to turn around his re-election campaign.

In “ Double Down,” journalists Mark Halperin and John Heilemann say that Obama followed up his presidential debate by conducting a “dismal” mock debate with then-Sen. John Kerry .

“If we don’t fix this, we could lose the whole f*ing election,” Obama advisor David Plouffe reportedly said following the mock debate.

Obama’s advisors attempted to shift his tone and approach in advance of the second presidential debate, leading Obama to respond, “I can’t tell you that ‘Okay, I woke up today, I knew I needed to do better, and I’ll do better.’ I am wired in a different way than this event requires. … I just don’t know if I can do this.”

For her part, Michelle Obama reportedly did not suffer from the same reservations as her husband, telling a group of female Obama campaign donation bundlers that the president had only lost the first debate because “Romney is a really good liar.”

It was the second such detail revealed from “Double Down” in recent days. On Thursday, an excerpt from the book revealed that Obama advisors explored the possibility of replacing Joe Biden on the vice presidential ticket with Hillary Clinton .

And while that excerpt also detailed the continually strained relationship between Obama and Bill Clinton, Saturday’s excerpt details how the former president was brought in to help Obama prepare for his second debate with Romney.

At a fundraising debate four days after the first debate, Bill Clinton reportedly told Obama, “Don’t try to make up the ground you lost … Just be yourself.”

Specifically, Clinton warned Obama to not try to compensate for his seemingly detached first debate performance by becoming too aggressive in the re-match.

Plouffee then tried to put the challenge in perspective for Obama.

“You’ve got basically 75 to 80 minutes left of doing this in your entire life. That’s less than the length of a movie!” Plouffe said. “I know it’s unnatural. But that’s all. That’s the finish line, you know?”