Democratic presidential candidate, Sen. Barack Obama, D-Ill., campaigns at the Ronald Reagan International Trade Center in Washington, Tuesday, July 15, 2008. Obama said Tuesday that overall U.S. interests have been hurt rather than helped by the Bush administration's decision to increase troop strength in Iraq 18 months ago, and vowed to stick to his plan to withdraw combat troops within 16 months of becoming president.
(AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama, D-Ill., looks downward as he is introduced by former Indiana Rep. Lee Hamilton, not pictured, at a campaign stop in Washington, Tuesday, July 15, 2008. Obama said Tuesday that overall U.S. interests have been hurt rather than helped by the Bush administration's decision to increase troop strength in Iraq 18 months ago, and vowed to stick to his plan to withdraw combat troops within 16 months of becoming president.
(AP Photo/Jae C. Hong)
White House hopeful Barack Obama speaks to attendees at the 99th annual convention of the National Association for the Advancement of Colored People (NAACP) at the Duke Energy Center July 14, 2008 in Cincinnati, Ohio. Obama Tuesday promised to shift the "single-minded" US focus on Iraq to a threatening "terrorist sanctuary" in tribal Pakistan, in a broad new blueprint for US foreign policy.
(AFP/Getty Images/File/Scott Olson)
Democratic presidential candidate Senator Barack Obama (D-IL) waves and smiles to the crowd after addressing supporters during a campaign stop at the NAACP National Convention in Cincinnati, Ohio, July 14, 2008. REUTERS/John Sommers II
Democratic presidential candidate, Sen. Barack Obama, D-Ill., greets supporters at the NAACP convention in Cincinnati, Monday, July 14, 2008.
(AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama, D-Ill., arrives at Midway International Airport in Chicago, Monday, July 14, 2008.
(AP Photo/Jae C. Hong)
U.S. Senator and Democratic Presidential candidate Barack Obama listens at campaign event in New York City, July 10, 2008. Obama said on Saturday comments by Iraqi leaders calling for a timetable for withdrawal of U.S. troops added weight to his stand in favor of such a timetable. (Mike Segar/Reuters)
U.S. Senator and Democratic Presidential candidate Barack Obama (D-IL), speaks at the National Council of La Raza convention in San Diego July 13, 2008.
REUTERS/Mike Blake
Democratic presidential candidate, Sen. Barack Obama, D-Ill., greets supporters after speaking at the National Council of La Raza Convention in San Diego, Calif., Sunday, July 13, 2008. (AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama, D-Ill., greets supporters after speaking at the National Council of La Raza Convention in San Diego, Calif., Sunday, July 13, 2008. (AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama, D-Ill., arrives in San Diego, Calif., Saturday, July 12, 2008. (AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama, D-Ill., waves as he leaves a hotel after a fundraiser in San Diego, Calif., Sunday, July 13, 2008.
(AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama, D-Ill., talks to reporters aboard his campaign charter en route to San Diego, Calif., Saturday, July 12, 2008. Obama says there's 'little doubt' the U.S. economy has moved into a recession, underscoring the need for a second economic stimulus package, steps to shore up the housing market and a long-term energy policy. (AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama, D-Ill., arrives at O'Hare International Airport in Chicago, Saturday, July 12, 2008.
(AP Photo/Jae C. Hong)
Democratic presidential candidate, Sen. Barack Obama D-Ill., arrives at a barber shop for a hair cut Saturday, July 12, 2008, in his Hyde Park neighborhood in Chicago.
(AP Photo/M. Spencer Green)
Democratic presidential candidate Sen. Barack Obama D-Ill., asks his media pool if they are going to see a movie with he and his family as he leaves the East Bank Club Saturday, July 12, 2008, in Chicago.
(AP Photo/M. Spencer Green)