In the case of Roy v. Blair, the United States Supreme Court holds that a state cannot constitutionally require its electors to vote for the candidates to whom they are pledged. There have been at least four instances in which individual electors failed to vote for their party’s candidate. The first occurred after the 1820 election, then 1956, 1960, and 1968, each peculiar to the wishes of an individual elector. None of these instances affected the election’s outcome.