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).
William Henry Harrison
Harrison's cabinet insisted that Tyler was "Vice President acting as President". After the cabinet consulted with the Chief Justice Roger Taney, they decided that if Tyler took the presidential Oath of Office, he would assume the office of president. Tyler obliged and was sworn into office on April 6, 1841. Congress convened in May, and after a short period of debate in both houses, it passed a resolution that confirmed Tyler as president for the remainder of Harrison's term. Once established, this precedent of presidential succession remained in effect until the Twenty-fifth Amendment was ratified in 1967, following the assassination of John F. Kennedy and the succession of Lyndon B. Johnson to the presidency in 1963. The Twenty-fifth Amendment dealt with the finer points of succession, defining the situations in which the vice president would serve as acting president, and in which situations the vice president could become president.