Democratic vice presidential nominee Senator Joe Biden (D-DE) (L) and Republican vice presidential nominee Alaska Governor Sarah Palin appear onstage during the vice presidential debate at Washington University in St. Louis, Missouri, October 2, 2008. REUTERS/Rick Wilking/Pool   (UNITED STATES)   US PRESIDENTIAL ELECTION CAMPAIGN 2008 (USA)  ST. LOUIS - OCTOBER 02: Democratic vice presidential candidate U.S. Senator Joe Biden (D-DE) speaks as Republican vice presidential candidate Alaska Gov. Sarah Palin looks on during the vice presidential debate at the Field House of Washington University's Athletic Complex on October 2, 2008 in St. Louis, Missouri. The highly anticipated showdown between the two vice-presidential candidates will be their only debate before the election. Getty Images logo Getty Images 9 months ago

Democratic vice presidential nominee Senator Joe Biden (D-DE) (L) and Republican vice presidential nominee Alaska Governor Sarah Palin appear onstage during the vice presidential debate at Washington University in St. Louis, Missouri, October 2, 2008. REUTERS/Rick Wilking/Pool (UNITED STATES) US PRESIDENTIAL ELECTION CAMPAIGN 2008 (USA) ST. LOUIS - OCTOBER 02: Democratic vice presidential candidate U.S. Senator Joe Biden (D-DE) speaks as Republican vice presidential candidate Alaska Gov. Sarah Palin looks on during the vice presidential debate at the Field House of Washington University's Athletic Complex on October 2, 2008 in St. Louis, Missouri. The highly anticipated showdown between the two vice-presidential candidates will be their only debate before the election.