https://en.wikipedia.org/wiki/Nuclear_option

In the United States Senate, the nuclear option is a legislative procedure that allows the Senate to override a standing rule by a simple majority, avoiding the three-fifths[1] supermajority normally required to invoke cloture on a measure. The term "nuclear option" is an analogy to nuclear weapons being the most extreme option in warfare.

The nuclear option was invoked on November 21, 2013, when a Democratic majority led by Harry Reid used the procedure to reduce the cloture threshold for nominations, other than nominations to the Supreme Court, to a simple majority.[3] On April 6, 2017, the nuclear option was used again, this time by a Republican majority led by Mitch McConnell, to extend that precedent to Supreme Court nominations, in order to enable cloture to be invoked on the nomination of Neil Gorsuch by a simple majority.[4][5][6]

The use of the nuclear option to abolish the 60-vote threshold for cloture on legislation has been proposed, but not successfully effected.