 One of the primary functions of the Supreme Court of the United States is to ensure that laws are interpreted uniformly among intermediate courts of appeal. Unless the legislature takes action, the United States Supreme Court is the only source of resolution for conflicts among intermediate courts of appeal. Consequently, the existence of a circuit split may be a key factor when the Supreme Court decides whether to accept a case. Although the Court always maintains discretion over whether it should grant review of a case, the Rules of the Supreme Court of the United States specifically state that the existence of a circuit split is one of the factors the Court considers when deciding whether to grant review. Philip Allen Lacovara and H.W. Perry both claim that the existence of a circuit split is "the single most important generalizable factor" that determines whether the Supreme Court will grant review of a case.
