Democratic presidential candidate, Sen. Barack Obama, D-Ill., right, and Democratic vice presidential candidate, Sen. Joe Biden, D-Del., are seen at the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Conventioneers cheer just before Democratic presidential candidate, Sen. Barack Obama, D-Ill., makes a surprise appearance at the Democratic National Convention to join his running mate, Sen. Joe Biden, D-Del., in Denver Wednesday, Aug. 27, 2008.
Democratic vice presidential candidate Sen. Joe Biden, D-Del., applauds as democratic presidential candidate, Sen. Barack Obama, D-Ill., speaks briefly during the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Democratic vice presidential candidate, Sen. Joe Biden, D-Del., addresses the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Democratic vice presidential candidate Sen. Joe Biden, D-Del., speaks during the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Democratic vice presidential candidate Sen. Joe Biden, D-Del., smiles on stage as his mother Jean Biden is seen on screen, rear, at the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Former President Bill Clinton speaks during the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Former President Bill Clinton addresses the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Former President Bill Clinton speaks during the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Sen. John Kerry, D-Mass., speaks during the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Sen. Hillary Rodham Clinton, D-N.Y., center, calls for the nomination of Sen. Barack Obama by acclamation at the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008. At right is New York Gov. David Paterson and at left is New York State Assembly leader Sheldon Silver.
CBS Evening News anchor Katie Couric listens as Sen. Hillary Rodham Clinton, D-N.Y., calls for the nomination of Sen. Barack Obama at the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008.
Colleen Burns, of Illinois holds back tears as she watches a video of Iraqi War Veterans during the Democratic National Convention at the Pepsi Center in Denver Wednesday, August 27, 2008.
Democratic presidential candidate Sen. Barack Obama, D-Ill., says "Let's go to Denver" as he boards a plane in Billings, Mont., to go to the Democratic National Convention, Wednesday, Aug. 27, 2008.
Senate Majority Leader Harry Reid, D-Nev., looks over the stage during a walk through during the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008. Reid is one of a number of speakers at Wednesday's session at the convention. Nominee for vice president, Sen. Joe Biden, and former President Bill Clinton will also address the convention.
Sen. John Kerry, D-Mass., right, jokes around with photographers during a walk-through at the Democratic National Convention in Denver, Wednesday, Aug. 27, 2008. Kerry will also address the convention. The roll call vote of the states will also be held.
Singer Melissa Etheridge, right, accompanied by guitarist Phillip Sayce, rehearses for a performance later in the day at the Democratic Convention in Denver, Wednesday, Aug. 27, 2008.
New Mexico Gov. Bill Richardson looks over the podium at the Democratic Convention in Denver, Wednesday, Aug. 27, 2008. Richardson is one of several speakers who will address the convention Wednesday.
Wounded Iraq veteran Tammy Duckworth looks on as silhouetted Michelle Obama, wife of democratic presidential candidate Sen. Barack Obama, D-Ill., talks to volunteers during Delegate Service Day at the 2008 Democratic National Convention in Denver, Wednesday, Aug. 27, 2008. On Wednesday night, two Iraq veterans, Duckworth, Rep. Patrick Murphy, D-Pa., will lead a tribute to soldiers and their families at the convention.
Musician Chris Daughtry performs with his band, Daughtry, at the GRAMMY's Rock The Conventions concert in Denver, late Tuesday Aug. 26, 2008.