The Supreme Court of the United States is the highest court in the federal judiciary of the United States
. It has ultimate appellate jurisdiction over all federal court cases, and over state court cases that involve a point of U.S. Constitutional or federal law
. The Supreme Court consists of the Chief Justice of the United States and such number of Associate Justices as may be fixed by Congress
. The number of Associate Justices is currently fixed at eight
. The Supreme Court's ultimate responsibility is to ensure the American people the promise of equal justice under law and, thereby, also functions as guardian and interpreter of the Constitution
. The best-known power of the Supreme Court is judicial review, or the ability of the Court to declare a Legislative or Executive act in violation of the Constitution
