Presidential Election '08 (50 images)

Former New York City Mayor Rudy Giuliani (L) speaks before the CNN/Los Angeles Times Republican presidential debate at the Ronald Reagan Presidential Library in Simi Valley, California on January 30, 2008 where he formally withdrew from the Republican presidential nomination race and endorsed rival US Republican presidential candidate John McCain (R-AZ) (C). At right is McCain's wife Cindy. (UPI Photo/Jim Ruymen)

Senator Barack Obama (D-IL) speaks to a crowd on the steps of City Hall in Oakland, California on March 17, 2007. (UPI Photo/Aaron Kehoe).

U.S. President George W. Bush and Republican presumptive presidential nominee Sen. John McCain (R-AZ) walk through the Colonnade on their way to speak to the media in the Rose Garden of the White House on March 5, 2008. Bush endorsed McCain's candidacy and pledged to support McCain during the campaign. (UPI Photo/Roger L. Wollenberg)

Presidential hopeful Sen. Hillary Rodham Clinton (D-NY) greets supporters after speaking at the College Democrats for America convention at the University of South Carolina in Columbia, South Carolina on July 28, 2007. (UPI Photo/Nell Redmond)