O n 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. Senate rules place no general limits on how long consideration of a nomination (or most other matters) may last. Owing to this lack of general time limits, opponents of a nomination may be able to use extended debate or other delaying actions to prevent a final vote from occurring. The use of debate and procedural actions for the purpose of preventing or delaying a vote is termed a "filibuster." The only procedure by which the Senate can vote to place time limits on its consideration of a matter is the motion for cloture provided for in paragraph 2 of Senate Rule XXII. This motion, therefore, is the Senate's most common means of attempting to overcome a filibuster. When the Senate adopts a motion for cloture on a matter, known as "invoking cloture," further consideration of the matter becomes subject to a time limit, and upon the expiration of that time, a vote will occur. For most matters, the time limit prescribed by the cloture rule is 30 hours, although under a standing order that was in effect only in the 113 th Congress (2013-2014), this 30-hour limit was lowered for all but high-level executive and judicial nominations. By invoking cloture, the Senate may be able to ensure that a question will ultimately come to a vote. Until November 21, 2013, however, the Senate could impose the constraints of cloture only by a supermajority vote. Three-fifths of the full Senate (60 votes, if there is no more than one vacancy) was required to invoke cloture. In earlier Congresses, as a result, even if a majority of Senators supported a nomination, opponents could possibly prevent a vote on it by defeating any attempt to invoke cloture, and continuing to extend consideration. As a result, although any nomination can always be approved by a simple majority of Senators present and voting, prior to November 2013 the support of a supermajority was required to limit consideration and enable the Senate to reach a vote. After the reinterpretation of the rule in November of 2013, the number necessary to invoke cloture was lowered to a simple majority, but other features of the cloture rule remained the same. With the new majority cloture rule, therefore, Senators can still extend post-cloture consideration of a nomination, within the limits of the cloture rule, including a limit of one hour of debate for each Senator and a total time limit of 30 hours of consideration on each nomination. The large number of nominations submitted to the Congress, particularly at the outset of a new presidential administration, can lead the majority to seek unanimous consent rather than cloture in order to approve nominations more quickly. Although cloture affords the Senate a means for overcoming a filibuster, it is erroneous to assume that cases in which cloture is sought are always the same as those in which a filibuster occurs. Filibusters may occur without cloture being sought, and cloture may be sought when no filibuster is taking place. The reason is that cloture is sought by supporters of a matter, whereas filibusters are conducted by its opponents. It is possible, as a result, that opponents of a matter may use debate and other procedural actions to delay a vote without supporters deciding to move for cloture. This situation appears not to be common today, but does seem to have occurred in relation to nominations in earlier times. Supporters may refrain from seeking cloture either because they think they lack the votes to obtain it, because they believe they can overcome any delaying actions and reach a vote without resorting to cloture, or because they hope to resolve the matter in dispute by some negotiated accommodation. On the other hand, leaders of the majority party, or other supporters of a matter, may move for cloture even when opponents deny that they are conducting a filibuster, or at a point when no extended debate or delaying actions have actually occurred. They may do so in response to a threat or perceived threat of a filibuster, or simply in an effort to speed action. It often appears that Senate leaders attempt to avoid bringing to the floor matters, including legislation as well as nominations, on which they foresee a likelihood that filibusters will occur. These agenda choices may be motivated in part by a desire to avoid expending scarce floor time on matters that cannot be brought to a successful conclusion. Compounding the potential for misunderstanding, in recent times observers have increasingly extended the use of the term "filibuster" to apply to situations in which opponents of a matter attempt in advance to discourage its consideration on the Senate floor. These situations are also sometimes described as "silent filibusters." They may arise, for example, when Senators inform their respective party floor leaders that they prefer the nomination (or other matter) not to receive floor consideration, an action that has become known as placing a "hold" on a matter. Although a "hold" has no formal procedural force under Senate rules, it may represent an implicit threat to filibuster that may discourage the majority leader from bringing the matter to the floor. This newer sense of the term "filibuster" is sharply distinct from the historically better-established usage described above, which refers to actions actually taken during floor consideration. Cloture motions cannot be used to identify "filibusters" in the sense of matters withheld from floor consideration, because action under the cloture rule is, itself, something that occurs only in the course of floor proceedings. Except by unanimous consent, indeed, cloture can be moved only on a question already pending on the floor. On matters on which a filibuster is in prospect, as a result, the possibility of cloture can arise only if the leadership determines to bring the matter to the floor despite the possibility of filibuster, and at that point the previously "silent filibuster" either becomes an overt filibuster or fails to materialize. Furthermore, in Congresses just prior to the reinterpretation of the rule, when the possibility of a filibuster was foreseen, the Senate occasionally agreed by unanimous consent to consider a nomination under time limits, but required 60 votes for its approval. Under this arrangement, the so-called "60-vote hurdle" or "60-vote threshold" preserved the possibility for a minority (if sufficiently large) to prevent approval, yet the time limit made it unnecessary to offer any cloture motion. As a result, these cases of potential filibuster also are not identifiable from the presence of cloture motions. The reinterpretation of the cloture rule further complicates using cloture motions as a method for identifying filibusters, particularly when making comparisons over time. After the reinterpretation of the rule, a Senate majority of the President's party became far more likely to attempt cloture. While the majority party might claim the increased use of cloture reflects increased obstruction by the minority, the minority might claim the increased use of cloture reflects a majority more readily and perhaps routinely relying on a simple majority process, regardless of any actual or perceived threat to filibuster. The incomparability of the periods before and after the rules reinterpretation made it inappropriate to extend the data presented in this report past the point of the rule reinterpretation. If cloture cannot serve directly as a measure of filibusters, however, neither can any other specific procedural action. A filibuster is a matter of intent; any proceedings on the floor might constitute part of a filibuster if they are undertaken with the purpose of blocking or delaying a vote. Yet any of the procedural actions that might be used to delay or block a vote might also be used as part of a normal course of consideration leading without difficulty to a final decision. As a result, filibusters cannot simply be identified by explicit or uniform criteria, and there is no commonly accepted set of criteria for doing so. Instead, determining whether a filibuster is occurring in any specific case typically requires a degree of subjective judgment. For all these reasons, it would be a misuse of the following data, which identify nominations on which cloture was sought, to treat them as identifying nominations subjected to filibuster. It would equally be a misinterpretation to assume that all nominations on which cloture was not sought were not filibustered (especially for periods before 1949, when, as discussed later, it first became possible to move cloture on nominations). This report provides data only on nominations on which cloture motions were offered. It is not to be taken as providing systematic data on nominations that were or were not filibustered. It would not be feasible to develop a list of measures filibustered unless a commonly accepted standard for identifying what constitutes filibustering could first be established. At most, the data presented here may be regarded as identifying some potentially likely cases in which a filibuster (by some appropriate definition) may have occurred prior to the reinterpretation of the cloture rule in 2013. The Senate first adopted a cloture rule (paragraph 2 of Rule XXII) in 1917. Until 1949, cloture could be moved only on legislative measures; nominations could not be subjected to cloture attempts. From 1949 through November 20, 2013 (81 st Congress through the start of the 113 th Congress), cloture was sought on 143 nominations. (This total and other data presented in this report do not include four failed cloture attempts on four nominations that occurred prior to November 21, 2013, because subsequent successful cloture votes were held on all four nominations after the reinterpretation of the rule.) Table 6 , following the text of this report, identifies the 143 nominations, the number of separate cloture motions filed on each, the ultimate outcome of the cloture attempt in each case, and the disposition of each nomination. As shown by the summary in Table 1 , the Senate invoked cloture on 59 of these 143 nominations. On another 56 of these nominations, cloture motions were offered, but never came to a vote, because the motions were withdrawn or vitiated by unanimous consent, or because they fell (that is, became moot before the cloture vote occurred). On the remaining 28 of the 143 nominations, the Senate voted against imposing cloture. Of the 143 nominations on which cloture was sought, 118 ultimately won confirmation. The 118 nominations confirmed include all 59 on which the Senate invoked cloture and all but three of the 56 on which no cloture vote occurred. Even among the 28 nominations on which the Senate voted only against cloture, 6 were nevertheless able to achieve confirmation (completing the total of 118 nominations confirmed). The remaining 22 nominations on which the Senate ultimately rejected cloture failed of confirmation, in each case because, at some point after the final vote to reject cloture, the nomination was withdrawn from consideration, so that no final vote occurred. Overall, none of the 25 nominations that failed of confirmation following a cloture motion was rejected by the Senate on an "up-or-down" vote. This pattern is consistent with Senate action on nominations generally; in contemporary practice, nominations that reach a final vote are very seldom rejected. The assertion is sometimes made that filibusters against nominations were infrequent until recent years. Little comprehensive knowledge, however, exists about such filibusters in earlier times. One reason is that until 1929, the Senate normally considered nominations in closed session. Until 1917, moreover, the Senate had no rule for bringing debate on any matter to a close, and even thereafter, as noted above, the cloture rule did not apply to nominations until 1949. For any earlier years, accordingly, it would not be even possible to try to use cloture as a measure of filibustering on nominations. Certainly, some historical accounts reference instances of lame duck sessions preceding a change in party control of the presidency in which the Senate generally declined to confirm nominations by the outgoing President. Even in these cases, however, it is not clear that the nominations often failed as a result of filibusters on the floor. There is, nevertheless, some reason to think that in earlier periods, filibustering on nominations was, indeed, infrequent. It is not clear, however, that this condition prevailed chiefly because Senate practice discouraged filibustering in such cases. Instead, it appears that Presidents often may have submitted nominations only after prior consultation with Senators. There also seems reason to suppose that often, when any Senators strongly objected to a nomination, the Senate might decline to bring the matter to the floor in the first place. The custom of "Senatorial courtesy," under which the Senate would decline to consider a nomination to a position in the home state of a Senator who declared the nomination "personally obnoxious" to him, represented an instance of such practices. To the extent that these suppositions are well founded, it might be said, in effect, that during these earlier periods, obstacles to the confirmation of nominations manifested themselves more often in the form of what today might be called "silent filibusters" than through overt opposition during floor consideration. The prevalence of such situations, of course, could not be ascertained from the examination of floor proceedings. Even after Senate rules began to permit the use of cloture on nominations in 1949, it was not deemed necessary to seek cloture on any until 1968 (90 th Congress), when a motion to proceed to consider the nomination of Supreme Court Associate Justice Abe Fortas to be Chief Justice was debated at length. After the Senate rejected cloture on the motion to proceed, 45-43, President Lyndon B. Johnson withdrew the nomination. In 1969 and 1970, the nominations of Clement F. Haynsworth and G. Harrold Carswell to the Supreme Court were defeated after lengthy debate, but no cloture motion was filed on either. When the Senate considered the nomination to the Supreme Court of William H. Rehnquist late in the 1971 session, however, cloture was quickly sought. Though the Senate did not invoke cloture (52-42), the nomination was subsequently confirmed. Cloture was sought on no other nomination until 1980. That occurrence was the first in which cloture was sought on a nomination to an executive branch position, that of William G. Lubbers to be General Counsel of the National Labor Relations Board. Cloture was invoked, and the nomination was confirmed. In the meantime, the majority required for invoking cloture on most matters, including nominations, had been changed in 1975 from two-thirds of Senators present and voting to three-fifths of the full membership of the Senate (60 votes, assuming no more than one vacancy). This change in the rules generally meant that the threshold for invoking cloture was lowered: if all 100 Senators participated in the vote, the previous rule required the votes of 67 to invoke cloture; the new rule normally required 60 votes, regardless of how many Senators participated. Since 1980, as Table 2 illustrates, the frequency with which nominations have been subjected to cloture attempts has continually tended to increase (a development that parallels a trend in the frequency of cloture motions overall). In this table (and Table 3 below), data on each Congress in which cloture was moved on more than 10 nominations are set forth separately, but data for suitable groups of consecutive Congresses with less frequent cloture action on nominations are consolidated in a single row. Not only do the data in Table 2 manifest a generally rising trend, but the pattern displayed in Congresses beginning with the 108 th (2003-2004) is sharply distinct from that of earlier ones. From the 90 th through the 107 th Congress (1967-2002), cloture was only once (103 rd Congress, 1993-1994) sought on more than five nominations. In the five Congresses from the 108 th through the 113 th (2003-2013), by contrast, cloture was only once (110 th Congress, 2007-2008) sought on fewer than 14 nominations. The 103 rd , 107 th , and 111 th Congresses were each the first of a new presidential Administration, so that the number of nominations to be considered was presumably large. Nevertheless, the new level of nominations with cloture attempts that was reached in the 103 rd Congress remained exceptional until the 108 th Congress, but the pattern of activity from then on has increasingly come to make the 103 rd Congress look like a forerunner of practices that became typical. It is also pertinent, however, that the President's party had a Senate majority in the six Congresses before 2014 in which cloture was sought on 12 or more nominations. This pattern suggests that highly controversial nominations may now be more likely to be brought to the Senate floor if it is the President's party that can set the agenda. In the 108 th Congress (2003-2004), the pattern of Senate action on nominations on which cloture was sought displayed several distinctive features. This was the Congress during which extensive contestation occurred over attempts to secure confirmation for a series of judicial nominations by President George W. Bush, and the prospect arose that an attempt would be made to change Senate rules for considering nominations through proceedings (known as the "nuclear" or "constitutional option") that would not require supermajority support. The maximum number of cloture motions offered on any single nomination was markedly higher in the 108 th Congress. Only three times previously had as many as three cloture motions been offered on a single nomination, and only four times subsequently have as many as two cloture motions been offered on the same nomination. In the 108 th Congress, by contrast, one nomination was subjected to seven cloture motions and another to four. These events suggest the intensity with which supporters of these nominations were attempting to secure Senate votes thereon. The pattern from that time until the reinterpretation of the rule, by contrast, suggests that Senate leaders became less willing to invest extensive floor time on attempts to secure confirmation for nominations that did not command sufficient support for cloture. The Senate in the 108 th Congress also rejected cloture with much greater frequency on nominations on which it was moved. In that Congress the Senate ultimately voted against cloture on more than three-quarters of such nominations, which suggests that opponents were persisting in contesting those nominations much more intensely than was otherwise the case. In all other Congresses (or, when cloture was attempted on only a few nominations in each of several consecutive Congresses, as shown in Table 2 , in the group of consecutive Congresses as a whole), the Senate ultimately voted against cloture on no more than one-quarter of the nominations in question. This finding reflects the observation offered earlier that only a few nominations have been blocked by failure to obtain cloture. Over the full period under examination, as shown by Table 3 , cloture action occurred on nominations to positions in the judiciary and in the executive branch in roughly comparable numbers. Until the 111 th Congress, however, a majority of the nominations on which cloture was sought were to positions on the federal bench. This circumstance perhaps reflected the Senate's traditional inclination to grant the President wide latitude in selecting officials to serve under him in executive branch positions. More generally, however, the relative emphasis on nominations to positions in the two branches has shifted sharply from one Congress to another. In both of the periods identified in Table 3 that cover several consecutive Congresses, as well as in the 108 th Congress (2003-2004) and the 112 th Congress (2011-2012), nominations to judicial positions were the main focus of cloture action. In the 103 rd (1993-1994), 109 th (2005-2006), 111 th (2009-2010), and 113 th (through November 21, 2013) Congresses, cloture motions on executive branch nominations were more prevalent. It is perhaps pertinent that the 103 rd and 111 th Congresses both included the period immediately following the inauguration of a new President, when presumably there were a large number of nominations to positions in the new Administration. As already observed, the only period during which cloture attempts on either class of nominations were rejected far more often than they were either invoked or abandoned occurred in connection with the broad struggle over President George W. Bush's judicial nominations in the 108 th Congress (2003-2004). On executive branch nominations in the 109 th (2005-2006) and 111 th (2009-2010) Congresses, on the other hand, either cloture was invoked, or no vote occurred, in especially high proportions. On an especially high proportion of judicial nominations on which cloture was attempted in the 112 th Congress (2011-2012), no cloture votes ultimately occurred, suggesting that cloture might have been moved on many of these nominations in response to perceived threats of filibuster that did not materialize or, perhaps, that proved susceptible of negotiated resolution. Few of the nominations on which cloture was attempted prior to the reinterpretation of the cloture rule were to positions of the first rank in the federal government. Only 4 have been to the Supreme Court, as shown in Table 4 , and only 11 to head Cabinet departments or to other positions sometimes accorded Cabinet rank by the President, as shown in Table 5 . In relation to offices at lower levels of the executive branch, it can be discerned from Table 6 that cloture attempts have occurred particularly often on nominations to positions in the Department of State and the Department of Justice.

Summary: The motion for cloture is available in the Senate to limit debate on nominations, as on other matters. Table 6 lists all nominations against which cloture was moved from 1949, when the Senate changed the cloture rule to allow it to be moved on nominations, until November 21, 2013, when the Senate reinterpreted the rule to lower the threshold for invoking cloture on most nominations from three-fifths of the Senate to a majority of Senators voting. The reinterpretation of the rule significantly altered the use of cloture in the Senate, such that conclusions drawn from the data in this report are not applicable to similar data collected since that time. The initial version of this report was written prior to the 2013 reinterpretation of the rule; the report will not be further updated to reflect cloture action on nominations after that time. Because cloture can be used to end consideration of a nomination, it can be used to overcome a filibuster against a nomination. Table 6 shows the outcome of each cloture attempt on a nomination through November 20, 2013, and the final disposition of the nomination. It would be erroneous, however, to treat this table as a list of filibusters on nominations. Filibusters can occur without cloture being attempted, and cloture can be attempted when no filibuster is evident. Moreover, it appears that Senate leaders generally avoided bringing to the floor nominations on which a filibuster seemed likely. There are no means to identify the merely threatened filibuster. From 1949 through November 20, 2013, cloture was sought on 143 nominations that were disposed of prior to the rule reinterpretation. On 59 of these nominations cloture was invoked, and on 55 others no cloture motion received a vote. All but 3 of these 114 nominations were confirmed. Only on the remaining 32 nominations did the Senate ultimately reject cloture; of these, 26 were not confirmed. Until 1968, cloture was moved on no nominations, and from then through 1978, it was moved on only two. Even thereafter, in no single Congress from the 96th through the 102nd (1979 through 1992) was cloture sought on more than three nominations, and in no Congress from the 104th through the 107th (1995 through 2002) was it sought on more than five. Between these last two periods, however, the 103rd Congress (1993-1994) foreshadowed a more recent pattern, with cloture action on 12 nominations. In every Congress between 2003 and 2013, except the 110th (2007-2008), cloture was attempted on at least 14 nominations. The same five Congresses that saw cloture action on 12 or more nominations were those in which the Senate minority was of the party opposite that of the President. In all the Congresses or periods identified, no more than a quarter of nominations with cloture attempts failed of confirmation, except in the 108th Congress (2003-2004), when almost 80% of nominations subjected to cloture attempts (mostly judicial) were not confirmed. Prominent in this Congress were discussions of making cloture easier to get on nominations by changing Senate rules through procedures not potentially subject to a supermajority vote. In the 112th Congress, by contrast, cloture was moved on a record 33 nominations (again mostly to judicial positions), but on 23 of these nominations, the nomination was confirmed without a cloture vote. Overall, cloture was sought on nominations to 74 executive and 69 judicial positions. Judicial nominations, however, predominated in the two Congress just noted and before 2003, except in the 103rd Congress (1993-1994). Executive branch nominations predominated in that Congress and the 111th (2009-2010), both at the beginning of a new presidential Administration, as well as in the 109th Congress (2005-2006) and the start of the 113th Congress (2013). Few of the nominations on which cloture was sought prior to the rule reinterpretation were to positions at the highest levels of the government. These included 4 nominations to the Supreme Court and 11 to positions at the Cabinet level.