Admiralty Jurisdiction: The Power Over Cases

“Admiralty jurisdiction” describes one of the three types of subject matter that federal courts may hear and decide. The phrase is unique, but it does not tell judges, counsel, and commentators (1) whether the phrase can mean one thing in the context of the Constitution and another thing in the context of the Judicial Code, (2) whether a particular matter is within or without the scope of the subject matter, (3) whether a matter can be moved into the scope by judicial decision or only by act of Congress, and (4) whether Congress can change the scope that the courts have defined. The key to answering these questions lies in the Constitution's words: not “jurisdiction,” but the judicial “power” over “cases.”