What is the filibuster?

The United States Constitution gives each chamber of Congress the authority to determine its own rules of procedure (Article I, Section 5). The House of Representatives uses a rules structure that typically limits debate and allows a simple majority to bring bills to a vote. The Senate, by contrast, developed a tradition of unlimited debate that goes back to the First Congress: unless a senator yields the floor or the Senate unanimously agrees to limit debate, any senator may speak for as long as they wish. Because a final vote on a bill cannot occur while debate is still open, this tradition created the structural possibility of indefinitely blocking legislation by refusing to stop speaking.

The term 'filibuster' entered American political vocabulary around the 1850s. It derives from the Dutch word 'vrijbuiter' (meaning freebooter or plunderer) via the Spanish 'filibustero,' which was used to describe pirates and mercenary adventurers who raided Latin American nations. American newspapers applied the term to senators who 'plundered' the legislative calendar by monopolizing debate. The first Senate cloture rule -- the procedural mechanism to end a filibuster by majority will -- did not exist until 1917. Before that, the only way to stop a filibuster was unanimous consent. This meant that a single determined senator (or a small group) could block legislation indefinitely.

Senate Rule XXII, the cloture rule, was adopted on March 8, 1917, by a vote of 76 to 3. The immediate catalyst was a filibuster by a small group of senators that prevented the Senate from voting on a bill to arm American merchant ships against German submarine attacks in the final days of the 64th Congress. President Woodrow Wilson publicly denounced the blockage. The 1917 rule required the signatures of 16 senators to file a cloture petition, and then a two-thirds vote of senators present and voting to invoke cloture and cut off debate. For the next 58 years, the two-thirds threshold was the rule for ending filibusters. In 1975, the Senate lowered the threshold to three-fifths of the entire Senate membership -- 60 of the 100 senators -- for most legislation, while retaining a two-thirds threshold for changes to Senate rules themselves.

By the late 20th century, senators rarely had to actually hold the floor for hours to sustain a filibuster. The 'silent filibuster' emerged as the norm: a senator (or group) notifies leadership that they intend to object to cloture, and the majority leader, lacking 60 votes, simply does not schedule the bill. Only occasionally does a senator stage an actual 'talking filibuster' -- holding the floor continuously. Senator Strom Thurmond set the all-time Senate record for a solo talking filibuster on August 28 and 29, 1957, speaking for 24 hours and 18 minutes against the Civil Rights Act of 1957. More recently, Senator Ted Cruz spoke for approximately 21 hours in September 2013 in opposition to the Affordable Care Act, though this did not technically delay a cloture vote on the legislation itself.

The 60-vote threshold has been partially dismantled through a procedural maneuver known as the 'nuclear option' or 'constitutional option.' Under this approach, the presiding officer rules -- on a point of order -- that a simple majority is sufficient to close debate on a particular class of nominations. A majority of senators then votes to uphold that ruling, effectively changing Senate precedent without amending Rule XXII (which itself requires a two-thirds vote to amend). On November 21, 2013, the Democratic-controlled Senate, led by Majority Leader Harry Reid, invoked the nuclear option by a vote of 52 to 48, eliminating the 60-vote threshold for all executive branch nominees and all federal judicial nominees except Supreme Court justices. On April 6, 2017, the Republican-controlled Senate, led by Majority Leader Mitch McConnell, extended the nuclear option to Supreme Court nominations by a vote of 52 to 48, enabling Neil Gorsuch's confirmation to the Supreme Court. As of 2026, the 60-vote cloture threshold remains in place for most legislation; nominations of all kinds require only a simple majority.

Certain categories of legislation bypass the filibuster entirely through special statutory procedures. The most significant is budget reconciliation, a process created under the Congressional Budget Act of 1974. A reconciliation bill may be passed by a simple majority in both chambers, but the Byrd Rule (added in 1985 and 1990) restricts its content to provisions that directly affect federal revenues, spending, or the debt limit. Provisions that have only incidental budgetary effects, or that would increase the deficit beyond the budget window, are subject to a 'Byrd bath' -- a point of order that strips non-compliant provisions unless 60 senators vote to waive the rule. Congress has used reconciliation to pass major legislation including the 1981 Omnibus Budget Reconciliation Act, the Tax Cuts and Jobs Act of 2017, and the Inflation Reduction Act of 2022. Other filibuster-exempt procedures include the Congressional Review Act, which allows a simple majority to overturn recent executive regulations.

For the 2028 presidential and Senate elections, the filibuster is directly relevant to the legislative agenda any administration can pursue. A president whose party controls fewer than 60 Senate seats -- the outcome in all recent Congresses -- cannot pass most legislation over unified minority opposition without either eliminating the legislative filibuster or reaching the 60-vote threshold through bipartisan compromise. Calls to abolish or further modify the filibuster recur each Congress; the debate centers on whether the 60-vote threshold protects minority rights and promotes deliberation or entrenches minority veto power at the expense of democratic accountability. Senate elections in 2028 will determine which party controls the chamber and with how many seats, shaping the legislative tools available to the next president. All 33 Class II Senate seats are up in 2028.