Article V establishes two methods for amending the Constitution, though only one has ever been used. Congress can propose amendments by two-thirds votes in both chambers, or two-thirds of state legislatures can call a constitutional convention to propose amendments. Either way, three-fourths of states must ratify any proposed amendment through their legislatures or special conventions before it becomes part of the Constitution. All 27 ratified amendments were proposed by Congress and ratified by state legislatures, except the 21st Amendment, which states ratified through conventions.
This deliberately difficult process requires overwhelming consensus at both federal and state levels, making the Constitution extremely hard to change. The framers wanted a stable foundation of government that would not shift with every political wind, yet remain adaptable when national agreement emerged on necessary changes. The president has no role in the amendment process—proposed amendments go directly from Congress to the states without presidential approval. This ensures the people, through their elected representatives in Congress and state legislatures, control constitutional change rather than any single executive. The difficulty of amendment explains why the Constitution has been changed only 27 times in over 235 years, despite thousands of proposed amendments introduced in Congress.