I'm not sure that a government official elected by the populace through the distillation of the electoral college qualifies de facto as a moral harbinger. Given the process through which an individual achieves the Presidency, I would suggest rather the opposite, at least in our time. A revisiting of The Best And The Brightest (David Halberstam) or Fear & Loathing On The Campaign Trail 1972 (Hunter Thompson) among others should clarify my meaning.