A two-thirds vote by both houses of Congress and a ratification vote of three-fourths of the states are required to amend the U.S. Constitution.
Explanation:
In order to amend the Consitution, the feat of a 'special majority' needs to be achieved every single time before the amendment of the Constitution is to be brought into effect.
The operations of voting of the Congress and the states are termed in both separate and combined manner as for passing the amendment, a vote of two-thirds of the United States Congress is deemed necessary, whereas, for the ratification of the amendment, a combined three-fourths vote of both the houses is required.
