	Introduction

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. 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. 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. Nonetheless, recusals are a rare occurrence on the Court. 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. 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. 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 .
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.