Twenty-second Amendment to the United States Constitution
The Twenty-second Amendment (Amendment XXII) to the United States Constitution sets a limit on the number of times an individual is eligible for election to the office of President of the United States, and also sets additional eligibility conditions for presidents who succeed to the unexpired terms of their predecessors.
Twentieth Amendment to the United States Constitution
Section 3 further refines the earlier mentioned Twelfth Amendment provision by declaring that if the president-elect dies before Inauguration Day, the vice president-elect will be sworn in as president on that day and serve for the full four-year term to which that person was elected; it further states that if on Inauguration Day a president-elect has not yet been chosen, or if the president-elect fails to qualify, the vice president-elect would become Acting President on Inauguration Day until a president-elect is chosen or the president-elect qualifies. Section 3 also authorizes Congress to determine who should be acting president if a new president and vice president have not been chosen by Inauguration Day. Acting on this authority, Congress added "failure to qualify" as a possible condition for presidential succession in the Presidential Succession Act of 1947. Previously silent on this point, the lack of guidance nearly caused a constitutional crisis on a couple of occasions: when the House of Representatives seemed unable to break the deadlocked election of 1800 and when Congress seemed unable to resolve the disputed 1876 election.