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).
Constitution of Singapore
Article 5A was introduced to deal with non-core constitutional amendments. The Article enables the President to veto proposed constitutional amendments that directly or indirectly circumvent or curtail the discretionary powers conferred on him by the Constitution. However, the power to veto is not absolute as the President may, acting on the Cabinet's advice, refer the matter to a constitutional tribunal under Article 100 for its opinion on whether a proposed amendment indeed has this effect. If the tribunal's view is different from the President's, the President is deemed to have assented to the bill on the day immediately following the day when the Tribunal pronounces its opinion in open court. However, if the tribunal upholds the President's view, the Prime Minister may refer the bill to a national referendum. The President's veto is overruled if not less than two-thirds of the total number of votes cast approve the proposed amendment. The President is deemed to have assented to the amendment on the day immediately following the day when the results of the referendum have been published in the "Government Gazette". This scheme prevents a gridlock that may arise if the Government calls for a new election to circumvent the President's veto. Thus, Article 5A provides a series of legal checks and balances between the President on the one hand, and the Prime Minister and Cabinet on the other. It increases the Constitution's rigidity as the power to amend the Constitution is no longer vested solely in Parliament.