A filibuster is the use of speaking privileges to delay or block a vote, typically in the U.S. Senate. The House of Representatives does not allow filibusters or anything equivalent. Several states, including Texas, have a procedure equivalent to a filibuster.
A filibuster can continue until the U.S. Senate approves either cloture or for the "nuclear option." From 1917 to 1975, cloture required a two-thirds vote of the Senate. The nuclear option can be adopted by a simple majority of those present. This option was first used in 1975 to revise the cloture rule so that a filibuster can be ended by a three-fifths majority (60 votes). The option has been used on only two other occasions, in 2013 and 2017. In both of these votes, the Senate revised the cloture rule in order to limit the use of the filibuster against presidential nominees.
In general parliamentary procedure, a filibuster is any tactic to delay and avoid a substantive vote by debating it at length, by offering numerous procedural motions, or by any other delaying or obstructive actions.
Democrats seek to end the 60-vote requirement in the U.S. Senate as part of the 2021-2022 session, during which Democrats expect to have a slim majority based on an independent senator from Maine who opposes changing this rule.
In practice, 19th century filibusters were successful only at the end of a session, when the clock was ticking. The Senate thereby refused to vote on the Wilmot Proviso regarding slavery in 1846.
In 1917 a bipartisan group of liberal isolationists led by Senator Robert LaFollette filibustered a bill to arm American merchant ships that were being attacked by German submarines. War had not been declared and the opponents thought big business was promoting a war with Germany. The filibuster stopped the legislation, but President Woodrow Wilson used his war powers to arm the ships anyway.
In 1941, on the eve of World War II, President Franklin D. Roosevelt, in an effort to integrate minority groups into the war effort, issued an executive order, with no vote in Congress, that created the Fair Employment Practices Committee and enlarged its responsibilities in 1943. It required companies with federal contracts to not discriminate against employees on the base of race, religion or ethnicity. However, only congressional action could extend its life beyond the war years. Democratic Senator Dennis Chavez of New Mexico introduced a bill to establish a permanent FEPC in 1945 which set off a national controversy over how much control the federal government should have in employment practices. Southern Democrats viewed the bill as a step toward social equality of the races. Leading the opposition was Senator Theodore Gilmore Bilbo (1877-1947) of Mississippi who vowed he would beat the 'damnable, unAmerican and unconstitutional' FEPC to death. The bill was withdrawn from consideration after a 24-day filibuster.
After 1917, the most famous filibusters were undertaken by Southern Democrats to block civil rights legislation. The record for the longest filibuster in the United States Senate is held by Senator Strom Thurmond, who filibustered against the Civil Rights Act of 1957 for 24 hours, 18 minutes.
The longest filibuster in any legislative body, 43 hours, was in the Texas State Senate (the upper chamber of the Texas Legislature), where Bill Meier of Tarrant County in 1977 filibustered against a worker's compensation bill that he considered "anti-business." Though his filibuster on that bill was unsuccessful (it ultimately passed 23-7) it drew attention to the underlying issues, ultimately resulting in a major overhaul of the state's worker's compensation system.
The right of unlimited debate in the Senate was rejected by the Founding Fathers. The Continental Congress adopted Rule 10. It followed the practice of the British Parliament and precedent allowed a simple majority to cut off debate by a motion for "the previous question." This rule was included in sections 8 and 9 of the rules adopted by the first Senate in 1789, was included in Jefferson's Manual of Parliamentary Practice, and was part of the Senate's rules until it was removed in 1806. The change in 1806 allowed unlimited debate, although this was not noticed until much later.
The fundamental issue to those who defend the right to filibuster has been the protection of minority rights. The desire to weaken presidential influence over the upper chamber, not free speech, was instrumental in the decisions of 1826 and 1828 that gave the Senate the ultimate authority to discipline its members. The defeat of the 1856 amendment requiring a Senator to confine himself to the question under debate marked the beginning of over a century of unrestricted debate. The defense of lengthy debate by John C. Calhoun was a matter of senatorial courtesy, but for his successors it became an inalienable, abstract right.
Until 1915, the Senate could end a filibuster by majority vote using a motion to suspend the rules. This motion is now rare in the Senate, but it is still a common means of limiting debate in the House of Representatives. In response to a successful filibuster of a bill to arm American merchant ships in 1917, the Senate adopted Rule 22. This rule requires a two-thirds vote to end a filibuster.
Originally, two-thirds of the senators actually present would be required for cloture. This meant that all senators had to remain present in the chambers, in case a cloture vote was called. This led to situations where senators would stay all night in the chambers, sleeping on cots placed in the lobby. This type of filibuster was depicted in the Frank Capra film, Mr. Smith Goes to Washington (1939), starring Jimmy Stewart as the brave lone hero who filibusters an evil bill.
Acting as president of the Senate, Vice President Richard Nixon ruled in 1957 that as a constitutional matter the Senate's internal rules could not prevent the body from adopting a measure by majority vote. This became known as the "nuclear," or constitutional, option. Nixon followed the Supreme Court's reasoning in United States v. Ballin, an 1892 case that dealt with the House of Representatives, and extended it to the Senate. The nuclear option was first used in 1975 to reduce the vote required to close debate from two-thirds to three-fifths.
In 1970, Majority Leader Mike Mansfield (D-Montana) created the "silent filibuster." This procedure allows the Senate to conduct other business while a senator uses Rule 22 to block the progress of a bill, and is overwhelmingly the most common filibuster used.
In 1975, the nuclear option, a simple majority vote conducted outside the normal rules of the Senate, was used to amend Rule 22. The number of senators required for cloture was reduced from 67 to 60. The two-thirds rule remained in effect when the Senate rules themselves were at issue.
As a result of these changes, almost all major legislation needs 60 votes to get to a final vote in order to pass the Senate. One exception comes in "reconciliation" bills that deal with the budget. Another is the use of "fast track" legislation, as with the North American Free Trade Agreement.
In May 2005, Republican leaders proposed what was called the "nuclear option" whereby filibusters would not be allowed on judicial nominations. Democrats threatened to disrupt all proceedings on all issues if that happened. Senator John McCain led a bipartisan "Gang of 14" which established a compromise that preserved the ability of senators to filibuster judicial nominees, but only in "extraordinary circumstances".
In November 2013, Senate leader Harry Reid used the nuclear option to revise the Senate's rules and allow presidential nominees to be confirmed by majority vote.
- DeNardis, Lawrence Joseph. "The New Senate Filibuster: An Analysis of Filibustering and Gridlock in the U.S. Senate, 1977-1986" PhD dissertation, New York U. 1990 50(9): 3042-A. DA9004195 350p.
- Kearny, Edward N., and Heineman, Robert A. "The Senate Filibuster: a Constitutional Critique." Perspectives on Political Science, 1997 Vol. 26, Issue 1, online at EBSCO
- Wawro, Gregory J., and Eric Schickler. Filibuster: Obstruction and Lawmaking in the US Senate, (2006) 366pp excerpt and text search
- The filibuster is called "chubbing" in the Texas House of Representatives. 
- Budget Reconciliation bills cannot be filibustered.
-  US Senate Reference
- Thomas W. Ryley, A Little Group of Willful Men: A Study of Congressional-Presidential Authority, (1975)
- Robert J. Bailey, "Theodore G. Bilbo and the Fair Employment Practices Controversy: a Southern Senator's Reactions to a Changing World," Journal of Mississippi History 1980 42(1): 27-42.
- Justin Dehn, Aman Batheja, and Alana Rocha (March 14, 2013). At 43 Hours, Texas Senator Set Filibuster Record in '77. The Texas Tribune. Retrieved on August 21, 2020.
- Richard R. Beeman, "Unlimited Debate in the Senate: the First Phase," Political Science Quarterly 1968 83(3): 419-434