What Is a Filibuster?

The term filibuster is used to describe a tactic used by members of the U.S. Senate to stall or delay votes on legislation. Lawmakers have used every trick imaginable to filibuster on the floor of the Senate: reading names from the phone book, reciting Shakespeare, cataloging all the recipes for fried oysters.

The use of the filibuster has skewed the way legislation is brought to the floor of the Senate. There are 100 members of the "upper chamber" in Congress, and most votes are won by a simple majority. But in the Senate, 60 has become the most important number. That's because it takes 60 votes in the Senate to block a filibuster and bring an end to unlimited debate or delay tactics.

Senate rules allow any member or group of senators to speak as long as necessary on an issue. The only way to end the debate is to invoke "cloture," or win a vote of 60 members. Without the 60 votes needed, the filibuster can go on forever.

Historic Filibusters

Senators have effectively used filibusters -- or more often, the threat of a filibuster -- to change legislation or block a bill from being voted on the Senate floor.

Sen. Strom Thurmond gave the longest filibuster in 1957 when he spoke for more than 24 hours against the Civil Rights Act. Sen. Huey Long would recite Shakespeare and read recipes to pass the time while filibustering in the 1930s.

But the most famous filibuster was conducted by Jimmy Stewart in the classic film Mr. Smith Goes to Washington.

Why Filibuster?

Senators have used filibusters to push for changes in legislation or to prevent a bill from passing with less than 60 votes. It is often a way for the minority party to yield power and block legislation, even though the majority party chooses what bills will get a vote.

Often, senators make their intent to filibuster known to other senators to prevent a bill from being scheduled for a vote. That's why you rarely see long filibusters on the Senate floors. Bills that will not be approved are rarely scheduled for a vote.

During George W. Bush's administration, Democratic senators effectively filibustered against several judicial nominations. In 2005, a group of seven Democrats and seven Republicans - dubbed the "Gang of 14" - got together to reduce filibusters for judicial nominees. The Democrats agreed not to filibuster against several nominees, while Republicans ended efforts to rule filibusters unconstitutional.

Against the Filibuster

Some critics, including many members of the U.S. House of Representatives who have seen their bills pass in their chamber only to die in the Senate, have called for an end to filibusters, or to at least lower the cloture threshold to 55 votes. They allege the rule has been used too often in recent years to block important legislation.

Those critics point to data that show the use of the filibuster has become too common in modern politics. No session of Congress, in fact, had attempted to break a filibuster more than 10 times until 1970. Since then the number of cloture attempts has exceeded 100 during some sessions, according to the data.

In 2013, the Democratic-controlled U.S. Senate voted to change the rules on how the chamber acts on presidential nominations. The change makes it easier to set up confirmation votes for presidential nominees for executive branch and judicial nominees with the exception of those for the U.S. Supreme Court by requiring only a simple majority, or 51 votes, in the Senate.