Cloture Attempts on Nominations: Data and Historical Development Through November 20, 2013 [September 28, 2018] [open pdf - 1MB]
"On November 21, 2013, the Senate reinterpreted Senate Rule XXII, lowering the number of Senators needed to invoke cloture on most nominations from three-fifths of the Senate to a simple majority. Cloture places time limits on consideration of a matter, and so may be employed as a means of overcoming filibusters. Since the reinterpretation of the rule, the use of cloture on nominations has changed considerably. This report was originally written prior to the reinterpretation of the rule. It presents data on all nominations on which cloture motions were offered from 1949, when the Senate altered the rule to allow cloture to be moved on any matter, including nominations, until November 20, 2013 (see Table 6). It also presents data on the outcomes of these attempts, the development over time of Senate practice in seeking cloture on nominations until the rule was reinterpreted, and the positions in relation to which cloture has been offered. Before entering into these discussions, the report sketches some general features of cloture and considerations pertinent to interpreting its meaning."
CRS Report for Congress, RL32878
Congressional Research Service: https://crsreports.congress.gov/