(CBS News) A new book,from journalists Mark Halperin and John Heilemann, reveals what may be the biggest secret from last year's presidential campaign: The White House considered replacing Vice President Joe Biden with then-Secretary of State Hillary Clinton.
In April of 2012, Clinton was asked in an interview if she was ready to run with President Obama. She said then, "That is not going to happen. That's like saying if the Olympic committee called you up and said, 'Are you ready to run the marathon, would you accept?' Well, it's not going to happen. ... It's more than unlikely."
CBS News contributor Bill Daley was the president's chief of staff at that time. He said he did ask aides to look into the idea of replacing Biden with Clinton but called it all an "over-hype" on the issue that has come with the book's release.
"CBS This Morning" co-host Charlie Rose pointed out this quote from the book, which pertains to Daley: "The top echelon of Obamaworld had, in fact, been discussing the wisdom of replacing Biden with Hillary, that, more than discussing it, they had been exploring it furtively and obliquely in the campaign's polling and focus groups and that Daley himself had been the most vocal proponent of looking into the merits of the idea."
Responding to that passage, Daley said, "One of the jobs of chief of staff is to recommend lots of things outside the box and to look at things, but not for a moment was there a serious discussion or a belief that Joe Biden should be replaced, period.
He continued, "That doesn't mean issues were not looked at. Lots of issues in 2011 were looked at. But ... anybody who would have brought this idea in to the president in the Oval Office, in my opinion, probably would have been thrown out immediately. But in 2011, part of my job, as I always saw, was to think outside the box and say, 'What if? And maybe we should look at this issue or that issue,' and it was looked at, but it was never seriously looked at in the sense that there was a belief that it ought to be done or needed to be done, and the truth is any research that was done confirmed the fact that that was not an issue that the voters cared about or thought that should be done, and the president, in my opinion, believed then, and I believe now, not for a moment would he ever consider that."
Asked if he acknowledges the what-if was asked, Daley said, "Yeah." Pressed further on the claim that there was polling and focus groups done on whether Clinton would help the ticket, Daley said, "There was research done on all sorts of issues and people and whether or not this or that. And that's a legitimate thing that campaigns do all the time. But it was not done. Surely it was not done with the intent that this ought to be done and there was need to do it."
Daley said, "But in 2011 ... it was a very difficult political year, and so my sense was we ought to look at everything here because this is a very- it was a very difficult period politically, but not for a moment, as far as I know, any of the senior people, surely including myself, thought that that was a good idea or needed to be done or should be done or whether the president would ever even seriously consider it if you thought it was the right thing to do. Nobody that I know of the senior people, including myself, thought at that point that it would be a good idea."
Though the book claims Clinton knew the research was being done, Daley said she "sure didn't find out from me."
Rose said, "You said (Heilemann), told you about it, that he knew that he thought she knew."
Daley replied, "As I say, that's news to me because this was not something that- obviously keeping a secret in some organizations is rather difficult, but I don't have any knowledge of whether or not she knew or anybody else."
For more with Daley, watch his full interview above.