Congress and Constitutional Amendments: How Congress Proposes Changes to the Constitution

The United States Constitution establishes two pathways for its own amendment, and Congress controls the most frequently used of those pathways at every stage before ratification. This page explains how Congress proposes constitutional amendments, what procedural and vote thresholds govern that process, which historical scenarios have defined its use, and where congressional authority ends and state authority begins. Understanding this mechanism is foundational to interpreting the scope of congressional powers and authority.

Definition and Scope

Article V of the U.S. Constitution (National Archives, Constitution of the United States) grants Congress the authority to propose amendments whenever two-thirds of both the House of Representatives and the Senate deem it necessary. This two-thirds supermajority requirement — 290 of 435 in the House and 67 of 100 in the Senate — distinguishes amendment proposals from ordinary legislation, which passes by simple majority.

Critically, Article V does not require the President to sign or approve a proposed constitutional amendment. In Hollingsworth v. Virginia (1798), the Supreme Court confirmed that presidential approval is not required for amendments to proceed to the states. This places the amendment proposal process outside the standard presentment clause that governs how a bill becomes law.

Congress's role is limited to proposal, not ratification. Once two-thirds of both chambers approve a proposed amendment, it is transmitted to the states. Ratification requires approval by three-fourths of state legislatures — 38 of 50 states — or by conventions in three-fourths of states, as Congress specifies. Congress may also set a time limit for ratification, typically 7 years, though the 27th Amendment (National Archives, 27th Amendment) was ratified 202 years after its original proposal in 1789, a gap that raised unresolved questions about the durability of unratified amendments.

How It Works

The congressional amendment process follows a structured sequence that differs in key ways from ordinary legislation:

1. Introduction. A joint resolution proposing a constitutional amendment is introduced in either chamber. Unlike a bill, a joint resolution for amendment does not go to the President for signature.
2. Committee referral. The resolution is referred to the relevant committee — typically the Senate Judiciary Committee or the House Judiciary Committee — for hearings and markup.
3. Supermajority floor vote. The full chamber votes. A two-thirds supermajority is required in both the House and the Senate. A simple majority is insufficient, regardless of how many cosponsors the resolution carries.
4. Transmission to states. Upon passage in both chambers, the Archivist of the United States — acting under 1 U.S.C. § 106b — transmits certified copies of the proposed amendment to the governors and state legislatures of all 50 states.
5. State ratification. Congress specifies whether ratification is to occur through state legislatures or state conventions. All 27 amendments ratified to date were ratified by state legislatures except for the 21st Amendment (1933), which used state conventions.
6. Certification. Once 38 states ratify, the Archivist certifies ratification and the amendment becomes part of the Constitution.

The amendment process stands in contrast to the congressional veto override process, which also requires a two-thirds vote but operates entirely within Congress and affects only a specific piece of legislation rather than the foundational legal document itself.

Common Scenarios

Three broad categories account for virtually every amendment proposal that has advanced through Congress:

Correcting structural deficiencies. The 17th Amendment (1912), establishing direct election of senators, corrected a perceived democratic deficit in the original design. The 25th Amendment (1967) addressed ambiguity about presidential succession and incapacity that had gone unresolved since 1787.

Expanding civil rights and suffrage. The 13th, 14th, and 15th Amendments (ratified 1865–1870) collectively abolished slavery, established birthright citizenship and equal protection, and prohibited race-based voting restrictions. The 19th Amendment (1920) prohibited denial of the right to vote on account of sex. The 26th Amendment (1971) lowered the voting age to 18, driven in part by arguments about military conscription.

Reversing Supreme Court decisions. Congress has used the amendment process to overturn specific constitutional interpretations by the Supreme Court. The 16th Amendment (1913) overturned Pollock v. Farmers' Loan & Trust Co. (1895), which had restricted the federal income tax. The 11th Amendment (1795) reversed Chisholm v. Georgia (1793) on state sovereign immunity.

Congress has introduced thousands of amendment proposals since 1789. Of those, only 33 have achieved the two-thirds threshold in both chambers, and of those 33, only 27 have been ratified. This highlights how deliberately high the supermajority barriers are set.

Decision Boundaries

Several boundaries define where congressional authority over amendments stops:

Congress cannot ratify. The ratification function belongs exclusively to the states under Article V. Congress has no authority to count, certify, or override individual state ratification votes once the proposal leaves Capitol Hill.

Congress cannot unilaterally rescind a proposal. Whether Congress can withdraw a proposed amendment before 38 states ratify remains constitutionally unsettled. Congress voted to extend the Equal Rights Amendment's ratification deadline in 1978 — a contested action that was never resolved by the courts.

Congress cannot bypass Article V. No statute, executive order, or congressional rule can amend the Constitution outside the Article V process. Legislative action that purports to modify a constitutional provision without going through Article V carries no constitutional effect and is subject to judicial invalidation.

The second Article V pathway excludes Congress. Article V also permits a constitutional convention called by two-thirds of state legislatures (34 states) to propose amendments. Congress plays no role in drafting proposals through that pathway, though it retains the authority to specify the mode of ratification. As of 2024, this convention pathway has never been successfully invoked (Congressional Research Service, "The Article V Convention to Propose Constitutional Amendments: Contemporary Issues for Congress," R42589).

The complete framework of congressional authority — from ordinary legislation to the most exceptional constitutional actions — is catalogued at the congressionalauthority.com index, which maps the full range of topics covered across this reference resource.