Barack Obama: Who will be his running mate?

Joe Biden, a senator from the small east coast state of Delaware, is considered a strong contender. As a longtime member and current chairman of the Senate foreign relations committee, Biden has helped shape US foreign policy in the Balkans, Afghanistan and Iraq - experience that could bolster Barack Obama's credentials Photograph: Paul J. Richards/Getty

Senator Evan Bayh represents a key swing state for 2008, Indiana, which has 11 electoral votes. Before heading to Capitol Hill, Bayh served as the mid-western state's governor, and his father, Birch Bayh, was an Indiana senator as well Photograph: Joe Raymond/AP

The governer of Virginia, Tim Kaine, endorsed Obama early in his campaign. Like Indiana, Virginia is considered a 'purple' state, split between red Republicans and blue Democrats Photograph: Brendan Smialowski/Getty

The governor of Kansas, Kathleen Sebelius, has been mentioned as a potential pick for Obama, primarily for her robust response to George Bush's state of the union address earlier this year. Education and environment issues have topped her agenda while in office Photograph: Alex Wong/Getty

Hillary Clinton, Obama's foe in the Democratic primary and a senator from New York, still has a base of support she could offer Obama. Clinton is scheduled to speak on the same night as Obama's eventual running mate at the Democratic convention in Denver - but will there be two speeches or one Photograph: Getty Images/Getty

Chet Edwards, a nine-term congressman from Texas, has gotten less buzz but enjoys the backing of one of America's most powerful politicians. 'I hope he will be the nominee,' House speaker Nancy Pelosi told ABC television earlier this month. Photograph: Rod Aydelotte/AP