US Senate Filibuster

The US Senate has a rule called a filibuster, which has been turned into a rule requiring 3/5 (60%) of Senators voting to pass a bill.

This rule is NOT in the US Constitution.

The Filibuster has been used to block most legislation by  requiringa supermajority of 60% voting for it.

History of the Filibuster

The Senate’s initial rules (1789) allowed unlimited debate, reflecting its design as a deliberative body. A "previous question" motion existed to end debate but was rarely used. In 1806, on Vice President Aaron Burr’s advice, the Senate eliminated this motion, inadvertently enabling prolonged debate, the foundation of the filibuster.

The Filibuster became an occasional tactic used in the 1830s to 1850s.  Examples include a debate over expunging President Andrew Jackson’s censure and pre-Civil War slavery debates. 

The Cloture Rule was added to limit Filibusters in 1917 because of frustration over the blocking of World War I legislation.   Cloture allowing a 2/3 majority to end debate, formalizing a counter to filibusters.

Filibusters were frequently used by Democrat senators to block civil rights legislation, such as anti-lynching and voting rights bills in the 1950s and 60s. An  example was the 1964 Civil Rights Act filibuster, which lasted 60 days before cloture was invoked.

The Senate reduced the cloture threshold in 1975 from 2/3 (67 votes) to 3/5 (60 votes), making it easier to end filibusters. 

By the 1990s and 2000s, filibusters became a standard tool for the minority party to block legislation and nominations, with "silent filibusters" (mere threats of delay) becoming common. The 60-vote threshold effectively became a de facto requirement for most Senate action.

In 2013, Democrats, eliminated filibusters for most nominations (except Supreme Court justices), requiring only a simple majority. In 2017, Republicans extended this to Supreme Court nominees, further limiting filibuster use for confirmations.

Currently, the filibuster remains for legislation in the Senate, requiring 60 votes to invoke cloture. Its frequent use has made it a contentious issue, with critics arguing it causes gridlock.  There is no longer any "debate" in a filibuster.  It has become simply 60 votes needed to pass legislature in the Senate.