'Double Down' Authors Reveal Behind-the-Scenes Look At 2012 Campaign

We're now learning that President Obama's top advisors actually staged an intervention to confront him about his poor performance in the 2012 debates, and told him he was blowing the election.

The revelation comes from journalists Mark Halperin and John Heilemann in their just-released book Double Down, the story of the 2012 campaign.

John Heilemann told INSIDE EDITION, "His top advisors sit down with him and say, 'Look, we have to get to the bottom of this. What's going on in your head, Mr. President?' The president says, 'You know, I don't really know if I can do this. I'm not wired this way.'"

Watch More of our Interview with the Authors Here

Remember the disasterous first debate, where the president appeared lethargic and disinterested? The authors say Obama set off alarm bells by tanking a practice debate right before the crucial second showdown with Romney.  

Heilemann said, "He's like, 'I'm a lawyer. This is not how I want to be. I'm not a circus performer. This is not how I want to do this.' They said, 'Look, you have to do this. If you don't do this, you could lose the election.'"

The pep talk worked. Obama rebounded dramatically in the second debate, attacking Romney right from the get-go.

The book also solves one of the great mysteries of the campaign—just where did Clint Eastwood get the idea for his bizarre empty chair speech at the Republican National Convention?  Halperin said, "He says to himself, 'I'm not going to give the same speech about how great Mitt Romney is. I'm going to do something different.'"

Believe it or not, the idea popped into Eastwood's head moments before he went onstage when he remembered this classic Neil Diamond lyric: "And no one heard at all...not even the chair."

Halperin explained, "The Neil Diamond lyric pops into his head. He's waiting to go out on stage. He says to the stage manager, 'You got a stool?' The stage manager says, 'Do you want a stool with a back, or a stool with no back?'"

The Double Down authors, who also wrote the bestseller Game Change about the 2008 election that was made into an Emmy-winning HBO movie, have now gotten into a political firestorm with New Jersey Governor Chris Christie over what their book says about him.

Romney aides used the nickname "Pufferfish" for Christie and Romney rejected him as a vice presidential running mate, partly over concerns about his weight.

Halperin told INSIDE EDITION, "Governor Romney thought that Chris Christie's weight was kind of fascinating. He'd see him take his suit jacket off and say, 'Wow, that guy is really big.' There were questions about his health. There's no doubt."

Romney spoke highly of Christie on Meet The Press Sunday when he said, "Chris could easily become our nominee and save our party and help get this nation on the right track again. They don't come better than Chris Christie."

Christie has since gotten lap band stomach surgery, but hasn't revealed how much weight he's lost.