The election of the president and the vice president of the United States is an indirect election in which citizens of the United States who are registered to vote in one of the fifty U.S. states or in Washington, D.C., cast ballots not directly for those offices, but instead for members of the Electoral College. These electors then cast direct votes, known as electoral votes, for president, and for vice president. The candidate who receives an absolute majority of electoral votes (at least 270 out of 538, since the Twenty-Third Amendment granted voting rights to citizens of D.C.) is then elected to that office. If no candidate receives an absolute majority of the votes for president, the House of Representatives elects the president; likewise if no one receives an absolute majority of the votes for vice president, then the Senate elects the vice president. In contrast to the presidential elections of many republics around the world (operating under either the presidential system or the semi-presidential system) which use direct elections from the national popular vote ('one person, one vote') of their entire countries to elect their respective presidents, the United States uses indirect elections (through the Electoral College) in order to elect the president and vice-president. As almost all states mandate the winner of the plurality of its constituent statewide popular vote ('one person, one vote') shall receive all of that state's electors ("winner-takes-all'), instances such as the presidential elections of 1824, 1876, 1888, 2000, and 2016 produced an Electoral College winner who did not receive the most votes in the general election; these were presidential elections in which the winner lost the popular vote due to the outsized effects of close and narrow pluralities in numerous swing states. The Electoral College and its procedure are established in the U.S. Constitution by Article II, Section 1, Clauses 2 and 4; and the Twelfth Amendment (which replaced Clause3 after its ratification in 1804). Under Clause2, each state casts as many electoral votes as the total number of its Senators and Representatives in Congress, while (per the Twenty-third Amendment, ratified in 1961) Washington, D.C., casts the same number of electoral votes as the least-represented state, which is three. Also under Clause2, the manner for choosing electors is determined by each state legislature, not directly by the federal government. Many state legislatures previously selected their electors directly, but over time all switched to