Then-Secretary of State Hillary Clinton and Vice President Biden at a White House event in October 2011. A new book says President Obama's aides were then studying whether to replace Biden with the former first lady on the 2012 ticket.
Kevin Dietsch /UPI /Landov
Children release 95 balloons to mark Nelson Mandela's upcoming birthday outside the Mediclinic Heart Hospital where Mandela is being treated for a recurring lung infection in Pretoria, South Africa.
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Former President George W. Bush and his successor, President Obama, at the April 25 dedication of Bush's library on the campus of Southern Methodist University in Dallas.
Larry W. Smith /EPA /LANDOV
President Obama walks across the tarmac to greet well-wishers on Sunday upon his arrival in Atlanta, Ga., where he will attend the commencement at Morehouse College.
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President Obama and GOP presidential nominee Mitt Romney walk away after they greet each other at the end of the third presidential debate in Boca Raton, Fla., on Monday.
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