In a Sept. 14, 2007 file photo retired U.S. Army General Wesley Clark is interviewed at his Little Rock, Ark., office. Clark, a former Democratic presidential candidate now supporting Barack Obama, said Sunday, June 29, 2008, John McCain's military service does not automatically qualify him to be commander in chief. (AP Photo/Danny Johnston)

In a Sept. 14, 2007 file photo retired U.S. Army General Wesley Clark is interviewed at his Little Rock, Ark., office. Clark, a former Democratic presidential candidate now supporting Barack Obama, said Sunday, June 29, 2008, John McCain's military service does not automatically qualify him to be commander in chief. (AP Photo/Danny Johnston)

U.S. Army Ret. Gen. Wesley Clark, front right, introduces Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y., at a campaign rally in Waco, Texas, Friday, Feb. 29, 2008. (AP Photo/Tony Gutierrez)

U.S. Army Ret. Gen. Wesley Clark, front right, introduces Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y., at a campaign rally in Waco, Texas, Friday, Feb. 29, 2008. (AP Photo/Tony Gutierrez)