The relationship between the 22nd and 12th amendments
Some have questioned the interpretation of the Twenty-second Amendment as it relates to the Twelfth Amendment, ratified in 1804, which provides that "no person constitutionally ineligible to the office of President shall be eligible to that of Vice-President of the United States."[8]
While it is clear that under the Twelfth Amendment the original constitutional qualifications of age, citizenship, and residency apply to both the president and vice president, it is unclear if a two-term president could later be elected—or appointed—vice president. Some argue that the Twenty-second Amendment and Twelfth Amendment bar any two-term president from later serving as vice president as well as from succeeding to the presidency from any point in the United States Presidential line of succession. Others contend that while a two-term president is ineligible to be elected or appointed to the office of Vice President, he could succeed from a lower position in the line of succession which he is not excluded from holding. Others contend that the Twelfth Amendment concerns qualification for service, while the Twenty-second Amendment concerns qualifications for election. Neither theory has ever been tested, as no former president has ever sought the vice presidency, and thus, the courts have never had an opportunity to decide the question.
The Amendment prohibits any person who has succeeded to the presidency and served as president or acting president for more than two years of their predecessor's unexpired term from being elected more than once. As of 2006, the only president who could have served more than two terms under this circumstance was Lyndon B. Johnson. He became president in 1963 when John F. Kennedy was assassinated, served only 14 months of Kennedy's term, and won an election of his own. Had he stayed in the race in 1968 and won, he would have served nine years and two months in all when he reached the end of the new term. The amendment specifically excluded the sitting president, Harry S. Truman. Truman began a campaign for a third term in 1952, but quit after a poor showing in the New Hampshire primary.
Gerald Ford became president on 9 August 1974 and was in office for more than 2 years of the unexpired term of Richard Nixon. Had Ford won a full term in 1976 (he narrowly lost to Jimmy Carter), he would have been barred from being elected again despite only being elected once.
Because there is less than two years remaining in George W. Bush's current term, Vice President Dick Cheney would not be restricted by this amendment if he were to succeed to the Presidency during the current term. He would be eligible to seek two additional full terms as President.