** FILE **In this Dec. 22, 1972, file photo, Sen. Joe Biden, D-Del. kisses the cheek of an unidentified friend who offered consoling words after a memorial service in Wilmington, Del., for Biden's wife Neilia, and their 13-month-old daughter Naomi Christina, who perished in a car-truck crash. Barack Obama told everyone he wanted a running mate who will challenge his thinking, and now he's got one. Joe Biden's tendency to speak his own mind _ and speak and speak _ is entwined in his DNA. (AP Photo/Bill Ingraham, File)