A filibuster is a tactic used by a minority group of members of the U.S. Senate who oppose and prevent the passage of a bill, despite the bill's having enough supporters to pass it. The tactic involves taking advantage of the rule that 60 votes are needed to stop debate on a bill. Debate on a bill can last indefinitely and must conclude before the bill can be voted on and passed.

The United States Senate is the upper chamber of the United States Congress, with the House of Representatives being the lower chamber. ... The Senate may end a filibuster by invoking cloture. In most cases, cloture requires the support of three-fifths of the Senate; however, if the matter before the Senate involves changing the rules of the ...