What the record really shows is just how much the fate of the Presidency is governed by the vagaries of chance.
After all, radically purist ideologies need to be sheltered from the vagaries of the world, and they can be expensive to maintain.
1570s, "a wandering, a roaming journey," probably from Latin vagari "to wander, roam, be unsettled, spread abroad," from vagus "roving, wandering" (see vague). Current meaning of "eccentric notion or conduct" (1620s) is from notion of mental wandering. Related: Vagaries.