number of electoral votes (in effect, three electors), although since that amendment's ratification the District's population has never reached the threshold that would otherwise entitle it to choose four or more electors. U.S. senators, representatives and federal government officials are barred from becoming electors; in practice, the two major federal parties frequently select senior state party and government officials (up to and including governors) to serve as electors. All states other than Maine (including the District of Columbia) use a first past the post system in their presidential elections. In 2020, Maine switched from first past the post to ranked choice. In McPherson v. Blacker (1892), the Supreme Court affirmed the ability of a state to appoint its electors based on electoral districts rather than a statewide popular vote, describing the power of state legislatures to determine the method of appointment of electors as "plenary", and suggesting that it was not limited even by state constitutions. In Bush v. Palm Beach County Canvassing Board (2000), the Supreme Court remanded to the Supreme Court of Florida the question of "the extent to which the Florida Supreme Court saw the Florida Constitution as circumscribing the legislature's authority under Art. II, § 1, cl. 2". In Williams v. Rhodes (1968), the Court struck down as a violation of the Equal Protection Clause an Ohio law which placed heavy burdens on minor parties seeking to be placed on the ballot for presidential electors. The Supreme Court upheld the power of Congress to regulate political contributions intended to influence the appointment of electors in Burroughs v. United States (1934). Clause 3: Electoral College In modern practice, parties nominate their electors through various methods, see Elector Nominations. Then, each state chooses its electors in popular elections. In most states, the party with the plurality of the popular vote gets all of its electors chosen. Once chosen, the electors meet in their respective states to cast ballots for the president and vice president. Originally, each elector cast two votes for president; at least one of the individuals voted for had to be from a state different from the elector's. The individual with the majority of votes became president, and the runner-up became vice president. In case of a tie between candidates who received votes from a majority of electors, the House of Representatives would choose one of the tied candidates; if no person received a majority, then