Part of his last speech on the WOT - to the American Legion I think. It may have been a clip because I wasn't listing that closely (to the radio).
He didn't use that term in that speech. See:
http://www.whitehouse.gov/news/releases/2006/08/20060831-1.html
He said, "They're successors to Fascists, to Nazis, to Communists, and other totalitarians of the 20th century."