Speaker of the United States House of Representatives by the President "pro tempore" of the Senate and by the heads of federal executive departments. To date, the implementation of the Presidential Succession Act has never been necessary and no Speaker has ever acted as President. Implementation of the law almost became necessary in 1973 after the resignation of Vice President Spiro Agnew. At the time, many believed that President Richard Nixon would resign because of the Watergate scandal, allowing Speaker Carl Albert to succeed to the Presidency. However, before he resigned, Nixon appointed Gerald Ford as Vice President in accordance with the Twenty-fifth Amendment. Nevertheless, the United States
Vice President of the United States presidential nomination at the convention. Of the thirteen presidential elections from 1956 to 2004, nine featured the incumbent president; the other four (1960, 1968, 1988, 2000) all featured the incumbent vice president. Former vice presidents also ran in 1984 (Walter Mondale) and in 1968 (Richard Nixon, against the incumbent vice president, Hubert Humphrey). The presidential election of 2008 was the first presidential election since 1928 that saw neither an incumbent president nor an incumbent or former vice president take part in any primary or general election for the presidency on a major party ticket. Nixon is the only vice president