The Constitution vests in the state legislatures the power to determine the manner in which to choose electors. This is plenary power—i.e. it can neither be taken from them nor abdicated. The Founding Fathers were worried about cabal, intrigue, and corruption infecting the vote for President, so the legislatures have a duty to guard against such abuses. Although they have vested the vote in the people, state legislatures retain their plenary power and the burden of ensuring our President is not raised to that high office by corrupt methods.