Presidential Succession

When a President dies, resigns, or is removed, the Vice President becomes President. The original Constitution left ambiguous whether the Vice President became President or merely acted as one, until John Tyler insisted on the full title after William Henry Harrison died in 1841. The Twenty-fifth Amendment, ratified in 1967 after John Kennedy's assassination, made the rule explicit and created procedures for filling a vice-presidential vacancy and for presidential disability.

Beyond the Vice President, the order is set by the Presidential Succession Act of 1947: the Speaker of the House, the president pro tempore of the Senate, and then the cabinet secretaries in the order their departments were created, from the Secretary of State to the Secretary of Homeland Security, eighteen officials in all. An official must meet the constitutional qualifications for President to serve. Because of this line, one cabinet member, the designated survivor, stays away from events such as the State of the Union that gather the other officials in one place.

Under Section 3 of the Twenty-fifth Amendment, a President can temporarily transfer power to the Vice President, who becomes acting President, by written declaration, as happened during medical procedures in 1985, 2002, 2007, and 2021. Section 4 lets the Vice President and a majority of the cabinet declare a President unable to serve, over the President's objection if Congress agrees by two thirds. Section 4 has never been invoked. Scholars have long questioned whether placing congressional leaders in the line is constitutional and whether the law adequately covers mass-casualty scenarios.