How a Filibuster Works

The Controversial Delay Tactic Used in the U.S. Senate

Sen. Strom Thurmond and the Filibuster
The record for the longest filibuster is held by the late U.S. Sen. Strom Thurmond of South Carolina, who spoke for 24 hours and 18 minutes against the Civil Rights Act of 1957.  Bettmann / Getty Images

A filibuster is a tactic used in the U.S. Senate to delay votes on controversial legislation or stifle debate on a topic. Typically, a senator wishing to filibuster will ask to speak on the floor of the chamber and, in an attempt to stall legislation action, hold forth for hours at a time. There are few rules that govern a filibuster because the Senate believes its members have the right to speak as long as they want on any issue. 

The filibuster dates to the early 1800s. The record for the longest filibuster is held by the late U.S. Sen. Strom Thurmond of South Carolina, who spoke for 24 hours and 18 minutes against the Civil Rights Act of 1957, according to U.S. Senate records. In the modern era, Republican U.S. Sen. Rand Paul of Kentucky staged a daylong filibuster in 2013 that captivated conservatives and libertarians as well as the national news media.

Critics call the filibuster unconstitutional at worst and unfair at best. Others believe it to be a historical relic. Practitioners of the filibuster insist that it protects the rights of the minority against the tyranny of the majority. By their nature, filibusters are meant to draw attention to a specific issues and have the potential to inspire compromise. According to the U.S. Senate, the word filibuster comes from a Dutch word meaning "pirate" and was first used more than 150 years ago to describe "efforts to hold the Senate floor in order to prevent action on a bill."

One Way to Break a Filibuster

Filibusters rules allow the delay tactic to go on for hours or even days. The only way to force the end of a filibuster is through parliamentary procedure known as cloture, or Rule 22, which was adopted in 1917. Once cloture is used, debate is limited to 30 additional hours of debate on the given topic.

Sixty members of the 100-member Senate must vote for cloture to stop a filibuster. At least 16 members of the Senate must sign a cloture motion or petition that states: "We, the undersigned Senators, in accordance with the provisions of Rule XXII of the Standing Rules of the Senate, hereby move to bring to a close the debate upon (the matter in question)."

Important Dates in the History of the Filibuster

​Here's a look at some of the most important moments in the history of the filibuster and cloture.

  • 1806: The U.S. Senate amends its rulebook in a way that unwittingly allows a member or members to stall action by speaking for hours on end. The Senate, acting at the request of Vice President Aaron Burr, eliminated a provision called the "previous question" rule that allowed the chamber to cut off floor debate. Without such a measure in place, a senator was permitted to speak indefinitely, paving the way for the filibuster.
  • 1841: Henry Clay threatens to change the Senate's filibuster rules to "allow the majority to close debate" when Democrats blocked a bank bill.
  • 1872: Vice President Schuyler Colfax rules that "under the practice of the Senate the presiding officer could not restrain a Senator in remarks which the Senator considers pertinent to the pending issue."
  • 1919: First use of Rule 22 when Senate invoked cloture to end debate against the Treaty of Versailles.
  • 1935: Populist U.S. Sen. Huey Long of Louisiana filibusters for 15 hours and 30 minutes trying, without success, to keep Senate oversight of National Recovery Administration's senior employees. How was he able to speak so long? He recited Shakespeare and read recipes for "pot-likkers," a Southern term for the broth created by cooking greens.
  • 1957: U.S. Sen. Strom Thurmond of South Carolina filibusters for a record 24 hours and 18 minutes as part of a move that successfully blocked the Civil Rights Act of 1957.
  • 1964: U.S. Sen. Robert Byrd of West Virginia filibusters for 14 hours and 13 minutes in an unsuccessful attempt to block the Civil Rights Act of 1964.
  • 1968: The Abe Fortas appointment to succeed Earl Warren as Chief Justice of the Supreme Court is derailed by Republicans through filibuster.
  • 2013: Republican U.S. Sen. Rand Paul of Kentucky filibusters for nearly 13 hours to question and raise awareness of the U.S. government's use of drones. It is the ninth-longest filibuster in history. "I will speak until I can no longer speak," he said. Paul ended his filibuster because he had to go to the bathroom.

[This articled was updated in May 2018 by Tom Murse.]