Article III section 2 gives SCOTUS original jurisdiction in cases in which a state shall be a party (at the federal level), and SCOTUS has ruled that one state's court does not have jurisdiction over another state, so any time one state sues another, SCOTUS acts as the trial court.
Article III section 2 gives SCOTUS original jurisdiction in cases in which a state shall be a party (at the federal level), and SCOTUS has ruled that one state's court does not have jurisdiction over another state, so any time one state sues another, SCOTUS acts as the trial court.