Republican presidential nominee Senator John McCain (L) and Democratic presidential nominee Senator Barack Obama shake hands after the first U.S. presidential debate at the University of Mississippi in Oxford, Mississippi, September 26, 2008. REUTERS/Brian Snyder (UNITED STATES) US PRESIDENTIAL ELECTIONCAMPAIGN 2008 (USA)

Republican presidential nominee Senator John McCain (L) and Democratic presidential nominee Senator Barack Obama shake hands after the first U.S. presidential debate at the University of Mississippi in Oxford, Mississippi, September 26, 2008. REUTERS/Brian Snyder (UNITED STATES) US PRESIDENTIAL ELECTIONCAMPAIGN 2008 (USA)

U.S. Republican presidential nominee Sen. John McCain (R-AZ) (L) and his Democratic opponent Sen. Barack Obama (D-IL) arrive onstage for their first presidential debate at the University of Mississippi in Oxford, Mississippi, September 26, 2008. REUTERS/Jim Bourg/Pool (UNITED STATES) US PRESIDENTIAL ELECTIONCAMPAIGN 2008 (USA)

Republican presidential nominee Senator John McCain (L) and Democratic presidential nominee Senator Barack Obama are introduced during the first U.S. presidential debate at the University of Mississippi in Oxford, Mississippi, September 26, 2008. REUTERS/Brian Snyder (UNITED STATES) US PRESIDENTIAL ELECTIONCAMPAIGN 2008 (USA)

Republican presidential nominee Senator John McCain (L) and Democratic presidential nominee Senator Barack Obama shake hands during the first U.S. presidential debate at the University of Mississippi in Oxford, Mississippi, September 26, 2008. REUTERS/Brian Snyder (UNITED STATES) US PRESIDENTIAL ELECTIONCAMPAIGN 2008 (USA)