Although most decisions of state courts falling within the Supreme Court's APPELLATE JURISDICTION involve questions of both state and federal law, the Supreme Court limits its review of such cases to the FEDERAL QUESTIONS. Moreover, the Court will not even decide the federal questions raised by such a case if the decision below rests on a ground of state law that is adequate to support the judgment and is independent of any federal issue. This rule applies to grounds based on both state substantive law and state procedures.
In its substantive-ground aspect, the rule not only protects the state courts' authority as the final arbiters of state law but also bolsters the principle forbidding federal courts to give ADVISORY OPINIONS. If the Supreme Court were to review the federal issues presented by a decision resting independently on an adequate state ground, the Court's pronouncements on the federal issues would be advisory only, having no effect on the resolution of the case. It has been assumed that ordinarily no federal policy dictates Supreme Court review of a decision resting on an independent state substantive ground; the winner in the state court typically is the same party who has asserted the federal claim. The point is exemplified by a state court decision invalidating a state statute on both state and federal constitutional grounds. This assumption, however, is a hindrance to Justices bent on contracting the reach of particular constitutional guarantees. In Michigan v. Long (1983) the BURGER COURT announced that when the independence of a state court's judgment from federal law is in doubt, the Court will assume that the judgment does not rest independently on state law. To insulate a decision from Supreme Court review now requires a plain statement by the state court of the independence of its state law ground.
Obviously, the highest state court retains considerable control over the reviewability of many of its decisions in
the Supreme Court. If the state court chooses to rest decision only on grounds of federal law, as the California court did in REGENTS OF THE UNIVERSITY OF CALIFORNIA V. BAKKE (1978), the case is reviewable by the Supreme Court. Correspondingly, the state court can avoid review by the Supreme Court by resting solely on a state-law ground, or by explicitly resting on both a state and a federal ground. In the latter case, the state court's pronouncements on federal law are...