What is cloture?

Cloture is the procedure used in the U.S. Senate to end a filibuster and proceed to a final vote on a bill, nomination, or other matter. Cloture allows the Senate to limit debate, which is otherwise unlimited under Senate tradition. Without cloture, a determined senator or group of senators can prevent the Senate from voting on a measure simply by continuing to debate it indefinitely.

The cloture rule was first adopted in 1917 under Senate Rule 22. The original rule required a two-thirds vote (67 senators if all 100 were present and voting) to invoke cloture and end debate. The cloture procedure was rarely used in the early 20th century, partly because few senators were willing to vote against debate, even on bills they ultimately supported. In 1975, the Senate reduced the threshold to three-fifths of duly chosen and sworn senators, which equates to 60 senators out of the full 100. This three-fifths threshold remains the rule for most matters today.

To begin cloture, 16 senators must sign a cloture motion to end debate. The motion ripens after one full day, after which the Senate votes. If 60 senators vote to invoke cloture, debate is limited to 30 additional hours, after which a final vote on the underlying matter is taken. If fewer than 60 senators vote for cloture, the filibuster continues and the underlying measure cannot proceed to a vote.

The 60-vote threshold has not always applied to every Senate action. The Senate eliminated the filibuster (effectively reducing the cloture threshold to a simple majority) for executive branch nominations and most judicial nominations in 2013, when the majority Democrats used what is called the nuclear option. Republicans applied the rules change to Supreme Court nominations in 2017, completing the elimination of the filibuster for all federal judicial confirmations. Both changes were made by a simple majority overruling a procedural ruling, effectively setting new precedent that nominations could proceed by simple majority.

The legislative filibuster remains, with cloture on most legislation still requiring 60 votes. Budget reconciliation, a procedure created in 1974, allows certain budget-related legislation to bypass the filibuster and pass with a simple majority. Reconciliation is limited by the Byrd Rule, which restricts what kinds of provisions can be included in reconciliation bills.

The cloture procedure has been used hundreds of times since 1917, particularly in recent decades. Cloture motions have multiplied as the Senate has become more polarized and the use of the filibuster has expanded. The rise in cloture motions reflects the growing role of supermajority requirements in shaping what the Senate can pass.