It takes one to know one: Biden's experience being picked by Obama shapes search for running mate

WASHINGTON - When his second presidential campaign collapsed in 2008 after a dismal showing in the Iowa caucuses, Joe Biden told reporters he had no interest in becoming someone else's vice president. He'd have more influence as chairman of the Senate Foreign Relations Committee, he figured.

Eight months later, he stood as running mate to the Democrat who beat him: Barack Obama, a man far below him in the Senate pecking order, much younger and less experienced in world affairs.

As Biden describes the process leading to that moment, it sometimes sounds like a buddy movie. But the Obama-Biden relationship was more complicated. Their attitudes toward each other changed significantly from the end of Biden's 2008 presidential race to his selection as vice president.

Now that experience is helping shape Biden's course as he seeks to find his own running mate, even as Obama has started taking a higher-profile role in this