Senate Rule XXII requires an affirmative vote of “three-fifths of the senators duly chosen and sworn” to invoke cloture, or end debate, on any “measure, motion, or other matter pending before the Senate…except on a measure or motion to amend the Senate rules, in which case the necessary affirmative vote shall be two-thirds of the senators present and voting.”
Consequently, cloture is typically understood today as making minority obstruction possible. A three-fifths vote is effectively required to schedule an up-or-down vote on most questions absent the unanimous agreement of all 100 senators. However, ending debate on presidential nominations only requires a simple-majority vote. (Democrats used the nuclear option to reduce the threshold to invoke cloture on most nominees in 2013 and Republican did the same for Supreme Court nominees earlier this year.)
Notwithstanding the recent use of the nuclear option, cloture remains a time-consuming process when the Senate is considering nominations and legislation. For most debatable measures, the entire process requires four calendar days to complete. This gives individual senators the ability to singlehandedly delay the consideration of the majority’s agenda on the Senate floor simply by withholding their consent to expedite the decision-making process. Given this, the number of cloture votes is frequently cited as evidence of minority obstruction.
But there is more to cloture than minority obstruction.