Twenty-second Amendment to the United States Constitution
The amendment prohibits any individual who has been elected president twice from being elected again. Under the amendment, an individual who fills an unexpired presidential term lasting greater than two years is also prohibited from winning election as president more than once. Scholars debate whether the amendment prohibits affected individuals from succeeding to the presidency under any circumstances or whether it only applies to presidential elections.
Vice President of the United States
Since 1977, former presidents and vice presidents who are elected or re-elected to the Senate are entitled to the largely honorific position of Deputy President pro tempore. To date, the only former vice president to have held this title is Hubert Humphrey following his return to the Senate. Also, under the terms of an 1886 Senate resolution, all former vice presidents are entitled to a portrait bust in the Senate wing of the United States Capitol, commemorating their service as presidents of the Senate. Dick Cheney is the most recent former vice president to be so honored.