Washington, Nov 1 (IANS): US President Barack Obama's top aides secretly considered replacing Vice President Joe Biden with Hillary Clinton on the 2012 ticket when Obama's re-election outlook appeared uncertain, according to the New York Times.

The bombshell revelation is provided by journalists Mark Halperin and John Heilemann, in their new book, "Double Down,"
giving an account of the 2012 US presidential race, the influential US daily reported.

However, the aides concluded that despite Clinton's popularity, the move would not offer a significant enough political boost to Obama to justify such a radical move, the book obtained by the Times "from people in the publishing industry" suggested.

The long rumoured dea of replacing Biden with Clinton was pushed by then chief of staff William M. Daley, despite the close personal rapport Daley had developed with Biden, a fellow Irish Catholic and veteran of Washington politics, it said.

"When the research came back near the end of the year, it suggested that adding Clinton to the ticket wouldn't materially improve Obama's odds," the authors are quoted as saying in their sequel to "Game Change," which chronicled the 2008 campaign.

"Biden had dodged a bullet he never saw coming - and never would know anything about, if the Obamans could keep a secret."

Daley acknowledged to the Times Thursday that he had wanted to research what the move would have meant for Obama, whose popularity, in the fall of 2011, was at its lowest in his presidency to date. He called it simply "due diligence."

The book also suggests that "even after Obama named Hillary Clinton as secretary of state, seemingly binding the wounds from their hard-fought 2008 primary campaign, he still could barely endure spending much time with the often-exhausting Bill Clinton."

Obama rarely contacted his Democratic predecessor in the first years after taking office, but after the midterm losses for his party, the incumbent and his inner circle realized that they needed the still-popular Clinton, it said.

But as the relationship between Obama and Clinton thawed during the campaign, the incumbent's bond with his vice president was tested, the Times said.