George Bush has variously claimed that he stopped telling jokes at media events and gave up golf because war demands seriousness, not comedy. Here he is at the United States Service Organisation (USO, which arranges entertainment for overseas forces) gala --
I think we all know the moment things began to turn around in Iraq: It was when the USO decided to deploy Jessica Simpson. (Laughter.)
Bush actually has a line in Jessica Simpson jokes, so one wonders if it's an obsession of him or a speechwriter.