Twenty-second Amendment to the United States Constitution
Some argue that the 22nd Amendment and 12th 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 presidential line of succession. Others contend that the original intent of the 12th Amendment concerns qualification for "service" (age, residence, and citizenship), while the 22nd Amendment, concerns qualifications for "election", and thus (strictly applying the text) a former two-term president is still eligible to "serve" as vice president (neither amendment restricts the number of times an individual can be elected to the vice presidency), and then succeed to the presidency to serve out the balance of the term (though prohibited from running for election to an additional term).
Term limit
Many modern presidential republics employ term limits for their highest offices. The United States placed a limit of two terms on its presidency by means of the 22nd Amendment to the Constitution in 1951. There are no term limits for Vice Presidency, Representatives and Senators, although there have been calls for term limits for those offices. Under various state laws, some state governors and state legislators have term limits. Formal limits in America date back to the 1682 Pennsylvania Charter of Liberties, and the colonial frame of government of the same year, authored by William Penn and providing for triennial rotation of the provincial council, the upper house of the colonial legislature. (See also term limits in the United States).