DENVER - AUGUST 27: The stage is ready for U.S. Democratic presidential nominee Sen. Barack Obamas (D-IL) acceptance speech tomorrow at Invesco Field, on day three of the Democratic National Convention (DNC) August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (R), his director of communications Robert Gibbs (L) and chief strategist David Axelrod tour the stage at Invesco Field where Sen. Obama will be delivering his acceptance speech tomorrow, on day three of the Democratic National Convention (DNC) August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (R) and U.S. Democratic vice presidential nominee Sen. Joe Biden (D-DE) stand together on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (C) walks onto the stage as he tours Invesco Field where Sen. Obama will be delivering his acceptance speech tomorrow, on day three of the Democratic National Convention (DNC) August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic vice presidential nominee Sen. Joe Biden (D-DE) holds his grandson Hunter after speaking on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Mark Wilson/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) points to his mother, Jean Biden, speaks after his nominating speech on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Spencer Platt/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Presidential nominee Sen. Barack Obama (D-IL) (L) and U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) stand together during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by John Moore/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton blows a kiss towards the box with wife U.S. Sen. Hillary Clinton (D-NY) and daughter Chelsea after his speech during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Win McNamee/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) walks with a family member on stage after his nominating speech on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by John Moore/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Presidential nominee Sen. Barack Obama (D-IL) (R) and U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) applaud during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Chip Somodevilla/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Chip Somodevilla/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (L) and U.S. Democratic vice presidential nominee Sen. Joe Biden (D-DE) stand together on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Chip Somodevilla/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Spencer Platt/Getty Images)more

DENVER - AUGUST 27: U.S. Sen. Barack Obama (D-IL) greets U.S. Sen. Nancy Pelosi (D-CA) after a surprise appearance at day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Justin Sullivan/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) and wife Jill Biden smile as U.S. Democratic Presidential nominee Sen. Barack Obama (D-IL) walks on stage during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Win McNamee/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Mark Wilson/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Win McNamee/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Chip Somodevilla/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Presidential nominee Sen. Barack Obama (D-IL) (L) speaks as U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) smiles during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Justin Sullivan/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) tours the stage at Invesco Field where Sen. Obama will be delivering his acceptance speech tomorrow, on day three of the Democratic National Convention (DNC) August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton waves to the crowd during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Mark Wilson/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Win McNamee/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Spencer Platt/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic Vice-Presidential nominee Sen. Joe Biden (D-DE) and wife Jill Biden hug during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by John Moore/Getty Images)more

DENVER - AUGUST 27: U.S. Sen. Barack Obama (D-IL) shakes hands with U.S. Sen. John Kerry (D-MA) on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Chip Somodevilla/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by John Moore/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (2R) along with his wife Michelle Obama (L) tour the stage at Invesco Field where Sen. Obama will be delivering his acceptance speech tomorrow, on day three of the Democratic National Convention (DNC) August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Sen. Barack Obama (D-IL) claps during a surprise appearance on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. Obama will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Win McNamee/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (R) and U.S. Democratic vice presidential nominee Sen. Joe Biden (D-DE) stand together on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (L) and U.S. Democratic vice presidential nominee Sen. Joe Biden (D-DE) stand together on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (R) flashes a thumbs up while on the stage with U.S. Democratic vice presidential nominee Sen. Joe Biden (D-DE) (C) on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Sen. Barack Obama (D-IL) shakes hands with U.S. Sen. Christopher Dodd (D-CT) on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Justin Sullivan/Getty Images)more

DENVER - AUGUST 27: U.S. Sen. Joe Biden (D-DE) stands on stage with family members during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Spencer Platt/Getty Images)more

DENVER - AUGUST 27: Convention goers attend day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Justin Sullivan/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton walks off stage during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by John Moore/Getty Images)more

DENVER - AUGUST 27: Former U.S. President Bill Clinton speaks during day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) will be officially be nominated as the Democratic candidate for U.S. president on the last day of the four-day convention. (Photo by Mark Wilson/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (R) greets former presidential candidate Sen. John Kerry (D-MA) on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more

DENVER - AUGUST 27: U.S. Democratic presidential nominee Sen. Barack Obama (D-IL) (L) and U.S. Democratic vice presidential nominee Sen. Joe Biden (D-DE) stand together on day three of the Democratic National Convention (DNC) at the Pepsi Center August 27, 2008 in Denver, Colorado. U.S. Sen. Barack Obama (D-IL) was officially nominated as the Democratic candidate for U.S. president by acclamation on the third day of the four-day convention. (Photo by Joe Raedle/Getty Images)more