Whether the Supreme Court had jurisdiction when the Michigan Supreme Court referred to both the Federal and State Constitutions.
Holding
Yes. The Michigan decision did not clearly and expressly rest on an adequate and independent state-law ground.
Reasoning
The Court reaffirmed that it cannot review a state-court judgment that rests on an adequate and independent state ground, because a federal ruling then could not affect the judgment and would be advisory. But the Court found its prior methods for identifying such grounds—dismissing unclear cases, examining unfamiliar state law, or remanding for clarification—too inconsistent, inefficient, and intrusive.
The Court adopted a plain-statement rule. When a state-court decision fairly appears to rest primarily on federal law, or is interwoven with federal law, the Court will presume that federal law controlled unless the state court clearly and expressly states that its result rests on a separate, adequate, and independent state ground. A state court may freely rely on federal decisions as persuasive guidance, but it must say plainly that federal law does not compel its result.
The Michigan Supreme Court’s opinion cited the Michigan Constitution, but otherwise relied exclusively on Terry and other federal cases. It cited no state cases as an independent basis for suppressing the evidence and expressly said that the intermediate court had misapplied Terry. The references to the state constitution therefore did not clearly establish an independent state-law basis for the judgment.