Twenty-second Amendment to the United States Constitution
As worded, the primary focus of the 22nd Amendment is on limiting individuals twice elected to the presidency from being elected again. Due to this, several issues could be raised regarding the amendment's meaning and application, especially in relation to the 12th Amendment, ratified in 1804, which states, "But no person constitutionally ineligible to the office of President shall be eligible to that of Vice-President of the United States". While it is clear that under the 12th Amendment the original constitutional qualifications of age, citizenship, and residency apply to both the president and vice president, it is unclear whether someone who is ineligible to be elected president could be elected vice president. Because of this apparent ambiguity, there may be a loophole in the 22nd Amendment whereby a two-term former-president could be elected vice president and then succeed to the presidency as a result of the incumbent's death, resignation, or removal from office (or even succeed to the presidency from some other stated office in the presidential line of succession).
President-elect of the United States
The words "president elect" appear four times in the Constitution, and they didn't appear until 1933, when the Twentieth Amendment, which contained a provision addressing the unavailability of the president elect to take the oath of office on Inauguration Day, was ratified. Section 3 provides that if there is no president-elect on January 20, or the president-elect "fails to qualify", the vice president-elect would become acting president on January 20 until there is a qualified president. The section also provides that if the president-elect dies before noon on January 20, the vice president-elect becomes president. In cases where there is no president-elect or vice president-elect, the amendment also gives the Congress the authority to declare an acting president until such time as there is a president or vice president. At this point the Presidential Succession Act of 1947 would apply, with the office of the Presidency going to the speaker of the House of Representatives, followed by the president pro tempore of the Senate and various Cabinet officers.