Certiorari

For much of its history the Supreme Court was required to hear many appeals, and by the 1920s its docket was badly backlogged. The Judiciary Act of February 13, 1925, known as the Judges' Bill and championed by Chief Justice William Howard Taft, gave the Court broad discretion to choose its cases through writs of certiorari, from the Latin for to be more fully informed. The Supreme Court Case Selections Act of 1988 eliminated almost all remaining mandatory appeals, so today nearly every case reaches the Court by petition for certiorari.

A party that loses in a federal court of appeals or a state's highest court may file a petition asking the Court to review the case, and the other side may respond. Most petitions are screened through the cert pool, in which law clerks from participating chambers write memos summarizing them. The Justices discuss promising petitions at private conferences, and by the rule of four, an unwritten tradition, review is granted if four Justices vote for it. The Court's rules say it looks mainly for important questions of federal law and conflicts among lower courts, known as circuit splits.

The Court receives about 4,000 petitions a year, many filed by prisoners without lawyers, and grants review in only about 60, a far smaller docket than the roughly 150 cases it decided each year in the 1980s. A denial sets no precedent and does not mean the Court agrees with the lower court, though Justices sometimes write dissents from denial. Supporters of the discretionary system say it lets the Court focus on the most significant questions, while critics say the Court takes too few cases, leaving conflicts unresolved, and that the selection process is opaque.