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.
Resign-to-run laws
Tex. Elec. Code § 145.001(e) permits a person to run for office and simultaneously be a candidate for President or Vice President of the United States. This statute permitted Lyndon B. Johnson to run for Vice President in 1960 and, at the same time, seek re-election as United States Senator from Texas. Lloyd Bentsen took advantage of the same provision in 1988 when he was the Vice Presidential running mate of Michael Dukakis.