The closing words of Article V of the Constitution of the United States protect one matter even when…

The proviso at the end of Article V provides that no State shall be deprived of its "equal Suffrage in the Senate" without its consent. Amendments are otherwise proposed by two thirds of both Houses of Congress or by a convention called on the application of two thirds of the State legislatures, and become valid when ratified by three fourths of the States, with no national referendum. The clause works like the German eternity clause in Article 79(3), though it can be overcome by the consent of the State concerned.