A supreme court is the most powerful member of a jurisdiction's judicial system. The U.S. Supreme Court is therefore the highest court in the nation. As such, it can act as an appellate authority in cases heard in lower courts. It can hear and decide cases between states and citizens of different states. The powers of the Supreme Court also allow it to hear and decide cases that arise from incidents on water and those involving foreign government representatives.
One of the primary powers of the supreme court is to hear appeals from cases that were decided in lower federal and state courts. If the U.S. Supreme Court finds errors in the previous decisions, it does not have to remand the cases back to be reheard. Instead, it has the authority to issue a different decision, which will be final and cannot be altered by any other judicial body. The powers of the Supreme Court also allow it to be selective with regard to the appellate cases that it hears. It does not have to hear every case that is submitted for its review, nor does the court attempt to.
State matters are usually heard in state court first. Then if a case makes its way far enough through the appellate process, it may end up before the U.S. Supreme Court. When the issue involves a legal dispute between two states, however, the Supreme Court has original jurisdiction, meaning it will be the first one to hear the case. This court may also have original jurisdiction when the parties to a case are citizens of different states and when citizens in one state file suit against a foreign state.
The powers of the Supreme Court give it authority over all cases involving admiralty. This refers to law that governs activity in waters such as lakes, river, and oceans. It applies even when the waters lie wholly within a specific jurisdiction and the parties are citizens of that jurisdiction. This means that if two boats crash in the Rappahanock River in Virginia, the matter will never be heard in that state's court.
The U.S. Constitution includes among the powers of the Supreme Court the ability to hear cases involving certain individuals. These include legal matters that involve citizens who hold positions such as ambassadors, public ministers, and consulates. The Supreme Court also has the authority to hear cases that involve foreigners who are government representatives.