used for the 1804 election. Each presidential election since has been conducted under the terms of the Twelfth Amendment. The Twelfth Amendment stipulates that each elector must cast distinct votes for president and vice president, instead of two votes for president. Additionally, electors may not vote for presidential and vice-presidential candidates who both reside in the elector's state—at least one of them must be an inhabitant of another state. If no candidate for president has a majority of the total votes, the House of Representatives, voting by states and with the same quorum requirements as under the original procedure, chooses the president. The Twelfth Amendment requires the House to choose from the three highest receivers of electoral votes, compared to five under the original procedure. The Twelfth Amendment requires a person to receive a majority of the electoral votes for vice president for that person to be elected vice president by the Electoral College. If no candidate for vice president has a majority of the total votes, the Senate, with each senator having one vote, chooses the vice president. The Twelfth Amendment requires the Senate to choose between the candidates with the "two highest numbers" of electoral votes. If multiple individuals are tied for second place, the Senate may consider them all. The Twelfth Amendment introduced a quorum requirement of two-thirds of the whole number of senators for the conduct of balloting. Furthermore, the Twelfth Amendment requires the Senate to choose a vice president by way of the affirmative votes of "a majority of the whole number" of senators. To prevent deadlocks from keeping the nation leaderless, the Twelfth Amendment provided that if the House did not choose a president before March4 (then the first day of a presidential term), the individual elected vice president would "act as President, as in the case of the death or other constitutional disability of the President". The Twelfth Amendment did not state for how long the vice president would act as president or if the House could still choose a president after March 4. Section3 of the Twentieth Amendment, adopted in 1933, supersedes that provision of the Twelfth Amendment by changing the date upon which a new presidential term commences to January 20, clarifying that the vice president-elect would only "act as President" if the House has not chosen a president by January 20, and permitting Congress to statutorily provide "who shall then