On February 13, 2016, Justice Antonin Scalia unexpectedly passed away at the age of 79, vacating a seat on the Supreme Court that he had held for nearly 30 years. A vacancy on the Supreme Court that arises during a presidential election year is a relatively rare occurrence, with the last such vacancy arising in 1968, when Chief Justice Earl Warren submitted a resignation letter less than six months before the general election. While Chief Justice Warren's seat was not filled until the following year, the last time a Supreme Court vacancy arose in an election year and the Senate approved a new appointee to the Court in that same year was 1932, when the seat vacated by the retirement of Justice Oliver Wendell Holmes Jr. in January of that year was filled by Justice Benjamin Cardozo two months later. Given this history and with suggestions that Justice Scalia's successor may not be confirmed for several months, let alone before the fall election, the possibility exists that Justice Scalia's seat on the High Court may remain open for an extended period of time, including throughout the remainder of the 2015 Supreme Court term. This report provides an overview of the Supreme Court's procedural rules and requirements when the Court is staffed with less than nine members. Included in this discussion is an overview of the Supreme Court's quorum requirements, rehearing procedures, and vote count practices, with a focus on how the Court has traditionally responded to a change of composition during a term. The report concludes by highlighting over a dozen cases from the current term that could result in an evenly divided Supreme Court. Article III of the U.S. Constitution provides that the judicial power of the United States shall reside in "one Supreme Court" and any lower courts Congress chooses to establish. Although the Constitution creates the Supreme Court, the nation's founding document is silent on the Court's makeup and design, and, as a result, Congress has generally exercised the authority to define the Court by statute. The first Congress, for example, enacted the Judiciary Act of 1789, which stated that the Supreme Court consists of "a chief justice and five associate justices." The size of the Court varied during the 19 th century, with the Court shrinking to five judges following the passage of the Judiciary Act of 1801 and growing as large as 10 judges after the enactment of the Judiciary Act of 1863. In 1869, Congress reduced the number of judges on the Supreme Court to nine, and the size of the Supreme Court remains the same today. In contrast to the federal appellate courts, the Supreme Court has, perhaps because of the constitutional establishment of "one" court, "always functioned as a single body, without dividing into panels." While the Supreme Court consists of nine Justices, it does not need nine Justices to decide a case. Instead, Congress has established quorum requirements for the Court, providing that any six Justices "shall constitute a quorum." By tradition, the agreement of a majority of the quorum is necessary to act for the Court. In recent years, the most likely reason for a Justice to be unavailable to participate in a proceeding before the Court has occurred when a Justice determines that he has a personal or financial interest in a case. Nonetheless, recusals are a rare occurrence on the Court. In the last five terms, only a handful of opinions have been released by an eight-member Court, and none have been released by a Court of seven or six members. If the Court is scheduled to hold a session but a quorum of Justices is not present, the Justices attending, or the Clerk or a Deputy Clerk, if no Justice is present, may announce that the Court will not meet until there is a quorum. Congress has delineated the procedures to be followed if the Supreme Court cannot hear or decide a case because of the absence of a quorum. These procedures differ depending on if the case is coming before the Court on direct appeal from a district court. While the majority of cases arrive at the Supreme Court from the lower appellate courts or are a part of the Court's original jurisdiction, a small number of cases, mostly respecting redistricting and campaign finance, come to the Court through a direct appeal after being heard initially by a three-judge district court. If the High Court cannot meet to rule on a case on direct appeal from a district court because of the absence of a quorum, Section 2109 of Title 28 allows the Chief Justice to remit the case to the court of appeals for the circuit that encompasses the district in which the case arose. Upon remittance to the appellate court, the lower court, sitting en banc or through a specially composed panel of three senior circuit judges, hears the case and renders a "final and conclusive" decision. In all other cases where a quorum is lacking, Congress has established that if a majority of the qualified Justices determine that the "case cannot be heard and determined at the next ensuring term, the court shall enter its order affirming the judgment of the court from which it was brought for review...." Such an order has no precedential value. A Supreme Court consisting of eight or six sitting members raises the possibility that the Court may be equally divided as to the outcome of a given ruling. In the absence of a full Court, when the quorum of Justices is evenly divided (four to four or three to three), the Supreme Court generally has taken one of two approaches. First, if the participating Justices are equally divided on the merits of a case, the Court's practice has, at times, been not to write an opinion, but to enter a judgment that tersely affirms the lower court judgment without any indication of the Court's voting alignment. In such a case, the judgment of the lower court would stand, but the Supreme Court's summary affirmance would not be accorded any value as precedent. For the Court, "no affirmative action can be had in a case where the judges are equally divided in opinion as to the judgment to be rendered or order to be made." As a consequence, as one commentator noted, "In baseball, a tie goes to the runner; in the High Court, a tie goes to the Respondent." The rule of affirmance by an equally divided court was most recently invoked in the 2010 term, when the Court split 4-4 on two cases in which Justice Kagan had recused herself. Second, in lieu of issuing a summary affirmance of the lower court opinion, the Court could instead order reargument of the case. The Court possesses inherent authority to order the reargument of a case sua sponte or on its own volition. The Court has, in the past, exercised such authority to have a case be reargued after identifying additional issues for consideration or determining that more time is needed to resolve a case. However, in a practice particularly relevant in the current circumstances, the Court has also ordered reargument in instances where the Court is equally divided and holding the case over for reargument could allow a new Justice to cast the deciding vote to create a majority opinion. For example, the abrupt resignation of Justice Abe Fortas in May of 1969 created a vacancy on the Court that was not filled until Justice Harry Blackmun took the oath of office on June 9, 1970. With several cases that were heard during the 1969 term resulting in an equally divided Court, the Court "reschedul[ed] an inordinate number of cases for reargument during the 1970 term." Similarly, upon Justice Kennedy's confirmation to the Court, filling a seat that had been vacant for more than seven months, the Court issued several orders allowing for reargument of cases that had previously been heard by an eight-member Court. Even short vacancies on the Court have resulted in reargument in closely divided cases. For example, at least one case, which was originally argued before an eight-member Court in October of 1991 after Justice Thurgood Marshall's retirement, was reargued so that newly appointed Justice Clarence Thomas could cast the decisive vote in the case. Most recently, in 2005, the Court, on its own initiative, provided for reargument in three cases that had originally been argued between the death of Chief Justice Rehnquist and the swearing-in of Justice Alito. It should be noted that it is not unprecedented for the Court to order reargument following the installment of new Justices even if there is not an equal division among the sitting members. Following the retirement of Justices Hugo Black and John Marshall Harlan II in the fall of 1971, the Court's remaining seven members heard oral argument in Roe v. Wade and Doe v. Bolton . After the confirmation of Justices Powell and William H. Rehnquist, Chief Justice Burger led an effort to have the cases reargued so that the two new Justices could participate in the decision. Justice Blackmun concurred, stating "I believe, on an issue so sensitive and so emotional as this one, the country deserves the conclusion of a nine-man, not a seven-man court." Ultimately, the Court heard reargument in both cases on October 11, 1972. The reargument resulted in a 7-2 decision in favor of abortion rights, although the votes of Justices Powell, who voted with the majority in both cases, and Rehnquist, who dissented in both cases, did not alter the outcome of the cases. In other words, in cases of special import or significance, reargument to allow a new Justice to participate in the case could be a possibility, regardless of whether there is a tie vote. Finally, it is also important to note that even if the Court chooses to issue a summary affirmance as the result of an equally divided Court, the petitioner (i.e., the party that initially asked the Court to hear the case) can request the Court to rehear the matter. Supreme Court Rule 44 permits an unsuccessful party to submit a petition for rehearing within 25 days of the entry of an adverse decision or judgment on the merits or denial of certiorari . In the context of a summary affirmance arising as a result of an equally divided Court, the petitioner, who sought to have the lower court's ruling reversed, may want to seek rehearing of the matter. Despite the existence of this option, as one commentator has noted, "the Supreme Court seldom grants a rehearing of any kind of order, judgment, or decision" upon the motion of a losing party. The infrequency with which petitions for rehearing are granted is likely due to the fact that the Court engages in a thorough consideration of each case prior to issuing a decision, making it unlikely that reargument of a case would change the outcome of even a closely divided Court. This principle generally adheres even when there is a change in composition of the Court, as rehearing will not be granted "except by a majority of the Court, at the instance of a Justice who concurred in the judgment or decision." Put another way, only if a Justice who agreed with the underlying decision now thinks rehearing is appropriate, and if a majority of the Court agrees in that decision, will rehearing be granted upon request. As a result, the Court generally will grant a petition for rehearing only in "exceptional situations" where the Court itself has "substantial doubts as to the correctness as to what it has decided, or where the unanticipated consequences of the Court's decision are clearly explained only in the rehearing petition." As such, while an unsuccessful petitioner could theoretically petition the Court for a rehearing in anticipation of a Court with a changed composition, the "more likely" vehicle for rehearing, where the Court is equally divided among its members, is for the Court to order a rehearing sua sponte . Given these rules and practices of the Court, the question that remains is how the Supreme Court will resolve the pending cases on its current docket absent Justice Scalia. This question is particularly appropriate given the unusual number of cases on the present docket that have been perceived to be highly controversial and likely to divide the Justices. Indeed, the Court during the 2015 term has heard or is scheduled to hear cases on public employee unions, abortion, immigration, and affirmative action, among other hot button issues. Predicting the outcome of any Supreme Court case, let alone some of the most high profile cases, is a difficult task, as the ultimate outcome of a case may depend on a number of complicated factors, not all of which are known to the public. Nonetheless, based on the current eight Justices' past voting practices and written opinions, several cases have been widely seen as having the potential to result in 4-4 splits in the absence of Justice Scalia. Table 1 provides a list of cases that could result in a 4-4 tie at the Court this year, including the outcome in the lower court, which would stand if five votes do not exist at the Supreme Court to reverse the lower court's ruling. Notably, absent from the list is Fisher v. University of Texas, a case challenging the use of racial preferences in college admissions at the University of Texas. When this case first reached the Court in 2013, Justice Kagan recused herself from the matter. Her recusal in the case currently before the Court will result in a seven-member Court deciding Fisher . While the Court's practice from Roe v. Wade and Doe v. Bolton may suggest that Fisher could be held over for reargument pending the appointment of a new Justice, the Court's willingness to opine on the underlying constitutional ruling two years ago in Fisher I with an eight-member Court may indicate that the Court could be willing to issue a ruling on the merits with a seven-member Court, as well. If the cases listed in Table 1 or others result in a 4-4 vote split, the Court will then have to decide between issuing a summary affirmance of the lower court ruling or having the case reargued when a new appointee fills Justice Scalia's seat on the Court. Justice Scalia's death occurs in the midst of a busy term at the Supreme Court, with dozens of pending cases remaining on the High Court's docket. Given the possibility that Justice Scalia's successor may not be confirmed in the near future, many of the Court's pending cases may result in a split vote between the current Justices. If such a situation arises, in light of the statutes, rules, and practices governing the Supreme Court, it appears the Court possesses significant authority and discretion in determining whether either (1) to issue an order summarily affirming the lower court's ruling; or (2) to allow a case to be reargued so that a new Justice can eventually participate in the ruling and settle the split on the High Court. The potential of many pending split decisions on the Court underscores the sign ificance of Justice Scalia's death for the 2015 term and the important role Justice Scalia's successor will serve on the Supreme Court. 

Summary: On February 13, 2016, Justice Antonin Scalia unexpectedly passed away at the age of 79, vacating a seat on the Supreme Court that he had held for nearly 30 years. Supreme Court vacancies that arise in presidential election years rarely occur, and have in the past led to a seat on the Court staying open for extended periods of time. With suggestions that Justice Scalia's successor may not be confirmed for several months, let alone before the fall election, a possibility exists that Justice Scalia's seat on the High Court may remain open for an extended period of time, including throughout the remainder of the 2015 Supreme Court term. While the Supreme Court consists of nine Justices, it does not need nine Justices to decide a case. Instead, Congress has established quorum requirements for the Court, providing that any six Justices "shall constitute a quorum." By tradition, the agreement of a majority of the quorum is necessary to act for the Court. As a consequence, with an eight-member Court, there is the possibility of split votes, where a majority cannot agree on the outcome in a given case. With several high-profile cases pending on the Court's docket, including cases on public employee unions, abortion, and immigration, it appears that the Court could become equally divided on a number of matters in the near future. In the absence of a full Court, when the quorum of Justices is evenly divided (four to four or three to three), the Supreme Court has empirically adopted one of two approaches. First, if the participating Justices are equally divided on the merits of a case, the Court's practice has, at times, been not to write an opinion, but to enter a judgment that tersely affirms the lower court judgment without any indication of the Court's voting alignment. Such an order has no precedential value. Second, in lieu of issuing a summary affirmance of the lower court opinion, the Court could instead order reargument of the case. The Court possesses inherent authority to order reargument of a case sua sponte or on its own volition, and has exercised such authority in the past when there was an open seat on the Court. In addition, an unsuccessful petitioner could petition the Court for a rehearing in anticipation of a Court with a changed composition. Nonetheless, the "more likely" vehicle for rehearing, where the Court is equally divided among its members, is for the Court to order a rehearing sua sponte prior to issuing a decision on the merits. This report provides an overview of the Supreme Court's procedural rules and requirements when the Court is staffed with less than nine members. Included in this discussion is an overview of the Court's quorum requirements, rehearing procedures, and vote count practices, with a focus on how the Court has traditionally responded to a change of composition during a term. The report concludes by highlighting over a dozen cases from the current term that could result in an evenly divided Supreme Court.