Democratic Vice Presidential nominee U.S. Senator Joe Biden (D-DE) with his son Beau Biden (L) acknowledge the audience at the 2008 Democratic National Convention in Denver, Colorado, August 27, 2008. Democrats nominated Senator Barack Obama (D-IL) on Wednesday as their presidential candidate in a historic first for a black American, sending him into battle against Republican John McCain. REUTERS/Mike Segar (UNITED STATES) US PRESIDENTIAL ELECTION CAMPAIGN 2008 (USA)