http://en.wikipedia.org/wiki/Wesley_Clark
He is the only potential candidate for 2008, who had a long military career as a general.
[quote:05ba4]Wesley Kanne Clark, KBE, (born December 23, 1944) is a retired four-star general in the U.S. Army. As the Supreme Allied Commander of NATO from 1997 to 2000, Clark commanded Operation Allied Force in the Kosovo conflict. Before this, he had a distinguished career in the Army and the Department of Defense. Clark received many military decorations over the course of his career. He was a candidate for the Democratic Party presidential nomination in 2004, but withdrew on February 11 after winning only the state of Oklahoma. Clark is reportedly being considered for Secretary of Defense if John Kerry wins in the 2004 presidential election.[/quote:05ba4]