How to Pass an Amendment to the U.S. Constitution

To pass an amendment to the U.S. Constitution, you need two supermajorities in sequence: two-thirds of both the House and Senate must propose it (or a convention called by two-thirds of state legislatures must do so), and then three-fourths of the states, currently 38 of 50, must ratify it. Article V lays out both stages, and no other route exists. Since 1789, members of Congress have introduced more than 11,000 amendment proposals. Twenty-seven have made it in.¹

Step One: Proposal by Congress

Almost every amendment that has ever been proposed started in Congress. Article V requires a two-thirds vote in both the House and Senate, and the threshold applies to members present and voting, assuming a quorum, not to the full membership of each chamber.² The often-quoted numbers of 290 House votes and 67 Senate votes assume every seat is filled and every member casts a vote. In practice, the number needed on any given day can be lower.

The proposal takes the form of a joint resolution. Unlike ordinary legislation, it does not go to the President. The Supreme Court settled that in Hollingsworth v. Virginia in 1798, where Justice Chase wrote that the President “has nothing to do with the proposition, or adoption, of amendments to the Constitution.”³ Once both chambers hit the two-thirds mark, the proposal moves straight to the states.

Step One, Alternative: A National Convention

Article V offers a second route that skips Congress. If two-thirds of state legislatures, currently 34, apply for a convention, Congress must call one for the purpose of proposing amendments.⁴ It has never happened. As of recent counts, at least 27 states have outstanding applications for a convention focused on a balanced budget amendment, and combined with states seeking a broader convention, the total reaches as high as 33 of the 34 needed.

Whether it could actually work is another question. The Constitution says nothing about how delegates would be picked, what rules would govern the proceedings, or whether the convention could be limited to a single subject. Scholars have argued these points for decades without settling them.² If the 34-state threshold were ever crossed, much of the process would be improvised.

Step Two: Ratification by Three-Fourths of the States

Once an amendment is proposed, 38 states must approve it before it becomes part of the Constitution.⁵ Congress chooses which of two mechanisms the states will use.

State Legislatures

This is the default and has handled 26 of the 27 ratified amendments. Each legislature votes under its own internal rules, some requiring a simple majority in both chambers and others adding procedural steps. When a state approves, it sends a formal ratification document, signed by the governor or secretary of state, back to the Archivist of the United States.

State Ratifying Conventions

Used exactly once, for the 21st Amendment repealing Prohibition in 1933.⁶ Congress picked conventions that time because many state legislatures were viewed as hostile to repeal even though public support was strong. The Constitution gives no direction on how states should run these conventions, and during the 21st Amendment’s ratification each state that held one followed its own procedures.⁷

Deadlines and the Clock

Article V sets no time limit for ratification. For the first 130 years, no proposed amendment carried one. The 18th Amendment, proposed in 1917, was the first to include a deadline, giving states seven years. Most amendments since have followed suit.

Where Congress puts the deadline matters. If it sits in the text of the amendment itself, it becomes part of the Constitution once ratified. If it sits in the “proposing clause” of the joint resolution, Congress has taken the position that it can extend or modify it, and did so in 1978 when it pushed the Equal Rights Amendment’s deadline from 1979 to 1982.

Without a deadline, an amendment can sit indefinitely. The 27th Amendment was proposed by James Madison in 1789 as part of the original Bill of Rights and was not ratified until 1992, more than 200 years later. In Coleman v. Miller (1939), the Supreme Court held that questions about whether a proposed amendment has lost its vitality with time are “political questions” for Congress, not the courts.

Can a State Take Back Its Ratification?

Almost certainly not. Article V says nothing about rescission, and history cuts against it. During ratification of the 14th Amendment, both Ohio and New Jersey tried to withdraw their approvals, and Congress counted them anyway. The Supreme Court’s approach in Coleman v. Miller treated the validity of ratifications, including attempted withdrawals, as a political question ultimately settled by Congress. No rescission has ever been recognized as valid, which means that once a state’s ratification is on the books, it stays on the books for counting purposes.

When the Amendment Actually Takes Effect

An amendment becomes part of the Constitution the instant the 38th state ratifies it. The paperwork that follows is confirmation, not the trigger. The Office of the Federal Register examines each state’s ratification document for basic legal sufficiency and an authenticating signature, then, once the count is complete, drafts a formal proclamation for the Archivist.⁴ Federal law says the Archivist “shall” publish the amendment with a certificate specifying which states adopted it and confirming that it has become valid as part of the Constitution.⁸ The Archivist has no discretion to refuse. The role is ministerial.

What Cannot Be Amended

Article V contains one permanent limit on its own reach: no state can be deprived of its equal representation in the Senate without that state’s consent.⁹ Roger Sherman introduced the protection at the 1787 Constitutional Convention out of concern that larger states could use amendments to dilute smaller states’ voting power. An amendment could in theory restructure or even abolish the Senate. It could not, however, give one state fewer senators than another without that state’s agreement. A separate Article V restriction on amendments affecting the slave trade or unapportioned direct taxes expired in 1808.

Why the Odds Are So Long

Of the more than 11,000 amendments introduced in Congress since 1789, only 33 cleared both chambers, and only 27 were ratified.¹ The success rate sits below a quarter of one percent. Supermajorities at both stages mean an amendment cannot pass on simple majority support. It needs something closer to national consensus, sustained across dozens of separate legislative bodies, often over years. That is the process, and it is designed to be hard.

1
Senate.gov. Measures Proposed to Amend the Constitution
2
Constitution Annotated. ArtV.1 Overview of Article V, Amending the Constitution
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Constitution Annotated. ArtV.3.4 Role of the President in Proposing an Amendment
4
National Archives. Constitutional Amendment Process
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National Conference of State Legislatures. Amending the U.S. Constitution
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Legal Information Institute. Ratification of the Twenty-First Amendment
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Constitution Annotated. Ratification by Conventions
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Office of the Law Revision Counsel. 1 USC 106b – Amendments to Constitution
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Constitution Annotated. Unamendable Subjects