Given his high ratings in most polls and the President's repeated public statements of confidence in him, Defense Secretary Donald Rumsfeld seems a cinch to remain secretary of Defense through the November election. But few are betting on the oldest-ever (72) secretary of Defense going the distance in a second Bush Administration. Sources say Deputy Homeland Security Secretary Gordon England and Reagan Navy Secretary John Lehman, a member of the 9-11 Commission, are on the short list to replace Rumsfeld.