Supermajority Vote in US Congress

U.S. Capitol Building in Washington, D.C.
U.S. Capitol Building in Washington, D.C.

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A supermajority vote is a vote that must exceed the number of votes comprising a simple majority. For example, a simple majority in the 100-member Senate is 51 votes and a 2/3 supermajority vote requires 67 votes. In the 435-member House of Representatives, a simple majority is 218 votes and a 2/3 supermajority requires 290 votes.

Key Takeaways: Supermajority Vote

  • The term “supermajority vote” refers to any vote by a legislative body that must get more votes than a simple majority of votes in order to win approval.
  • In the 100-member United States Senate, a supermajority vote requires a 2/3 majority or 67 of 100 votes.
  • In the 435-member United States House of Representatives, a supermajority vote requires a 2/3 majority or 290 of 435 votes.
  • In the U.S. Congress, several major legislative actions require a supermajority vote, most notably impeaching the president, declaring a president incapable of serving under the 25th Amendment, and amending the Constitution.

Supermajority votes in government are far from a new idea. The first recorded use of supermajority rule took place in ancient Rome during the 100s BCE. In 1179, Pope Alexander III used a supermajority rule for papal elections at the Third Lateran Council. 

While a supermajority vote can technically be specified as any fraction or percentage greater than one-half ( 50%), commonly used supermajorities include three-fifths (60%), two-thirds (67%), and three-quarters (75%).

When Is a Supermajority Vote Required?

By far, most measures considered by the U.S. Congress as part of the legislative process require only a simple majority vote for passage. However, some actions, like impeaching presidents or amending the Constitution, are considered so important that they require a supermajority vote.

Measures or actions requiring a supermajority vote:

  • Impeaching: In cases of impeachment of federal officials, the House of Representatives must pass articles of impeachment by a simple majority vote. The Senate then holds a trial to consider the articles of impeachment passed by the House. Actually convicting an individual requires a 2/3 supermajority vote of the members present in the Senate. (Article 1, Section 3)
  • Expelling a Member of Congress: Expelling a member of Congress requires a 2/3 supermajority vote in either the House or Senate. (Article 1, Section 5)
  • Overriding a Veto: Overriding a presidential veto of a bill requires a 2/3 supermajority vote in both the House and Senate. (Article 1, Section 7)
  • Suspending the Rules: Temporarily suspending the rules of debate and voting in the House and Senate requires a 2/3 supermajority vote of the members present. (House and Senate rules)
  • Ending a Filibuster: In the Senate only, passing a motion to invoke "cloture," ending extended debate or a "filibuster" on a measure requires a 3/5 supermajority vote - 60 votes. (Rules of the Senate) Rules of debate in the House of Representatives preclude the possibility of a filibuster.

Note: On November 21, 2013, the Senate voted to require a simple majority vote of 51 Senators to pass cloture motions ending filibusters on presidential nominations for Cabinet secretary posts and lower federal court judgeships only.

  • Amending the Constitution: Congressional approval of a Joint Resolution proposing an amendment to the U.S. Constitution requires a 2/3 majority of those members present and voting in both the House and Senate. (Article 5)
  • Calling a Constitutional Convention: As a second method of amending the Constitution, the legislatures of 2/3 of the states (33 states) can vote to request that the U.S. Congress convenes a constitutional convention. (Article 5)
  • Ratifying an Amendment: Ratification of an amendment to the Constitution requires the approval of 3/4 (38) of the state legislatures. (Article 5)
  • Ratifying a Treaty: Ratifying treaties requires a 2/3 supermajority vote of the Senate. (Article 2, Section 2)
  • Postponing a Treaty: The Senate may pass a motion to indefinitely postpone its consideration of a treaty by a 2/3 supermajority vote. (Senate rules)
  • Repatriating Rebels: An outgrowth of the Civil War, the 14th Amendment gives Congress the power to allow former rebels to hold office in the U.S. government. Doing so requires a 2/3 supermajority of both the House and Senate. (14th Amendment, Section 3)
  • Removing a President from Office: Under the 25th Amendment, Congress can vote to remove the president of the United States from office if the vice president and the president's Cabinet declare the president unable to serve and the president contests the removal. The removal of the president from office under the 25th Amendment requires a 2/3 supermajority vote of both the House and Senate. (25th Amendment, Section 4) Note: The 25th Amendment is an effort to clarify the process of presidential succession.

'On-the-Fly' Supermajority Votes

The parliamentary rules of both the Senate and House of Representatives provide means by which a supermajority vote can be required for the passage of certain measures. These special rules requiring supermajority votes are most often applied to legislation dealing with the federal budget or taxation. The House and Senate draw authority for requiring supermajority votes from Article 1, Section 5 of the Constitution, which states, "Each chamber may determine the Rules of Its Proceedings."

Supermajority Votes and the Founding Fathers

In general, the Founding Fathers favored requiring a simple majority vote in legislative decision-making. Most of them, for example, objected to the Articles of Confederation's requirement for a supermajority vote in deciding such questions as coining money, appropriating funds, and determining the size of the army and navy.

However, the framers of the Constitution also recognized the need for supermajority votes in some cases. In Federalist No. 58, James Madison noted that supermajority votes could serve as a "shield to some particular interests, and another obstacle generally to hasty and partial measures." Alexander Hamilton, too, in Federalist No. 73, highlighted the benefits of requiring a supermajority of each chamber to override a presidential veto. "It establishes a salutary check upon the legislative body," he wrote, "calculated to guard the community against the effects of faction, precipitancy, or of any impulse unfriendly to the public good, which may happen to influence a majority of that body."

The Supermajority Vote in the States

In most states, only a simple majority vote is required to pass any type of ballot initiative measure. By contrast, in almost all states, a supermajority vote of the state legislature is necessary to send a measure to amend the U.S. Constitution to the voters for ratification. All states except Delaware also require a vote of the people to pass a constitutional amendment. As once explained by Founder John Adams, Supermajority votes are intended to prevent allowing a “tyranny of the majority,” and to encourage deliberation and compromise as proponents attempt to gather enough votes to reach a supermajority. Thus, supermajorities in the state legislatures are often required for state or U.S. constitutional amendments because of the belief that constitutions should not be amended without careful deliberation. Many states also require a supermajority vote of the legislature to pass legislation dealing with taxation. Several states also require a supermajority vote to pass their state's budget. 

In most states, however, voter ballot initiatives proposing constitutional amendments are not subject to the same supermajority vote requirement as those proposed by the state legislature. Some legal experts question why supermajorities are required of the legislature but not of the people. They argue that the ballot initiative process lacks the checks found in the legislature that promote compromise and consensus and suggest that a supermajority vote requirement might help to prevent the passage of initiatives that are supported only by a narrow majority.

 In 1997, the supermajority requirement was challenged in court by supporters of a Wyoming ballot initiative that received a simple majority but failed to reach the supermajority requirement. In the 1996 general election in Wyoming, there was an initiative on the ballot calling for the passage of an amendment to the United States Constitution setting term limits for members of the United States Congress.

In the election, 105,093 votes were cast in favor of the ballot initiative while only 89,018 votes were cast against the measure. However, the Wyoming Secretary of State ruled that the measure failed to pass because of a provision in the Wyoming Constitution requiring that for the initiative to be enacted it needed to receive a favorable vote “in an amount in excess of fifty percent (50%) of those voting in the general election.” This meant that the measure would have required a favorable vote of 107,923, whereas those voting in favor were only 105,093.

On July 15, 1998, the 10th U.S Circuit Court of Appeals rejected the challenge, finding that Wyoming had the right to prevent “... abuse of the initiated process and make it difficult for a relatively small special-interest group to enact its views into law.” The case was appealed to the U.S. Supreme Court, which upheld the Circuit Court ruling.

View Article Sources
  1. Oleszek, Walter J. "Super-Majority Votes in the Senate." Congressional Research Service, 12 Apr. 2010.

  2. Mackenzie, Andrew. "An Axiomatic Analysis of the Papal Conclave." Economic Theory, vol. 69, Apr. 2020, pp. 713-743, doi:10.1007/s00199-019-01180-0

  3. Rybicki, Elizabeth. "Senate Consideration of Presidential Nominations: Committee and Floor Procedure." Congressional Research Service, 4 Apr. 2019.

  4. "Supermajority Vote Requirements." National Conference of State Legislatures.

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Longley, Robert. "Supermajority Vote in US Congress." ThoughtCo, Apr. 5, 2023, Longley, Robert. (2023, April 5). Supermajority Vote in US Congress. Retrieved from Longley, Robert. "Supermajority Vote in US Congress." ThoughtCo. (accessed June 1, 2023).