What Is a Filibuster?

A filibuster is a procedural tactic used in the United States Senate to delay or block a vote on legislation, nominations, or other matters by extending debate indefinitely. Unlike the House of Representatives, where debate time is strictly limited, the Senate’s rules allow any senator to speak for as long as they wish unless a supermajority of 60 senators votes to invoke cloture, which ends debate and forces a vote. The filibuster has its roots in the early Senate’s tradition of unlimited debate, though it was not formally codified until the adoption of Rule XXII in 1917, which established the cloture procedure. Over the decades, the threshold for cloture has been modified — notably in 2013, when the Senate eliminated the filibuster for most presidential nominations, and in 2017, when it was further eliminated for Supreme Court nominations. The legislative filibuster, which still requires 60 votes to overcome, remains one of the most debated features of Senate procedure. Supporters argue it protects minority rights and encourages bipartisan compromise. Critics contend it enables obstruction and gridlock on major policy issues.

This entry is part of the Republican Leaders Political Glossary, an educational reference on American government, legislative processes, and civic institutions.