<P> The nuclear option is a parliamentary procedure that allows the United States Senate to override a rule or precedent by a simple majority of 51 votes, instead of by a supermajority of 60 votes . The option is invoked by the presiding officer of the body ruling that the validity of a Senate rule or precedent is a constitutional question . The issue is immediately put to the full Senate, which decides by majority vote . The procedure thus allows the Senate to decide any issue by majority vote, regardless of existing procedural rules, such as current Senate rules specifying that ending a filibuster requires the consent of 60 senators (out of 100) for legislation, and 67 for amending a Senate rule . The term "nuclear option" is an analogy to nuclear weapons being the most extreme option in warfare . </P> <P> The nuclear option has only been used in practice twice (in 2013 and 2017), however the threat to use it dates back at least to 1917, in opinions related to reform of the Senate's filibuster rules . Subsequently, an opinion written by Vice President Richard Nixon in 1957 concluded that the U.S. Constitution grants the presiding officer the authority to override existing Senate rules . The option was used to make further rule changes in 1975 . In November 2013, Senate Democrats used the nuclear option to eliminate filibusters on executive branch nominations and federal judicial appointments other than those to the Supreme Court . On April 6, 2017, Senate Republicans used the nuclear option to eliminate the exception for Supreme Court nominees, after the nomination of Neil Gorsuch failed to meet the requirement of 60 votes for ending the debate . </P> <P> Before November 2013, Senate rules required a three - fifths vote of the "duly chosen and sworn" members of the Senate (usually 60 votes) to end debate on a bill, nomination or other proposal; they also require a two - thirds vote ("present and voting"--67 or more votes) to end debate on a change to the Senate rules . Those rules effectively allowed a minority of the Senate to block a bill or nomination through the technique of the filibuster . This had resulted in a de facto requirement that a nomination have the support of 60 Senators to pass, rather than a majority of 51 . A three - fifths majority vote is still required to end debates on legislation . Before April 2017, Senate rules required a three - fifths vote to confirm nominations for Supreme Court nominees . </P> <P> Under the new nuclear option proceedings, the majority leader and presiding officer, guided by parliamentary experts, go through a series of choreographed steps in which the leader asserts that the rules do not mean what they say, the presiding officer challenges him, and then the leader calls a vote to overrule the presiding officer, which requires only 51 votes . This effectively ends what had become a 60 - vote requirement for confirmation of a Supreme Court nominee or the passage of legislation . </P>

Amount of votes needed to pass a bill in the senate