At the time to choose your companion of iron Obama not opted for Hillary (for fear this would then undermine him or because he Ba’th several of their constituents) or by someone who would reinforce his image of change (but which do not appeal to other voters), but by a character in a field opposite within your same party that contrabalancee your figure. Obama Anointed Biden as his Vice President. It can not make you shady (he had little support when in 1988 and 2008 ran for the Democratic nomination and is very old). Biden is from labor and Catholic (two sectors where Obama is weak). Biden initially supported the invasion of Iraq and attacked Obama of being unprepared to be President, but to include it, the African-American shows a bridge for those who have a different vision.
It also seeks to repel accusations that is a novice taking a vice that has been six times elected to the Senate and three times has led the Committee on Foreign Affairs in the upper House. In addition, the U.S. elections are decided in a few hesitant States and one of them is Pennsylvania, where Biden has much influence.