The Supreme Court’s conservative bloc may be preparing an attack on state sovereignty in order to maintain a Republican gerrymander through the 2018 midterms. Last week, the Pennsylvania Supreme Court invalidated the state’s current congressional map, ruling that it favored the GOP in violation of the state constitution and ordering a new, nonpartisan map. Republican legislative leaders asked Justice Samuel Alito, who reviews emergency appeals out of Pennsylvania, to block the decision. Because the Pennsylvania Supreme Court decision involved only state law, Alito should’ve denied the request outright. Instead, he has ordered voting rights advocates to respond, raising the real possibility that a majority of the justices will vote to halt the ruling. If they do, the intervention will mark an extraordinary expansion of the court’s power to prevent states from protecting their residents’ voting rights.
To understand why the U.S. Supreme Court’s intrusion would be so radical here, it’s important to remember a key feature of the Pennsylvania Supreme Court’s holding. The court did not rule that the state’s gerrymander infringes upon any provision of the U.S. Constitution. Instead, the court held that partisan redistricting runs afoul of the Pennsylvania Constitution, which guarantees “free and equal” elections as well as an unusually robust right to free expression and association. These protections go beyond the rights of free speech and suffrage contained in the U.S. Constitution.
By rooting its decision in the state constitution, the Pennsylvania Supreme Court should have insulated its holding from review by the U.S. Supreme Court. Basic principles of federalism, or the balance between states and the national government, bar federal courts from overruling state supreme courts on an interpretation of state law. Thus, the U.S. Supreme Court can only reverse state supreme court decisions that misconstrue federal law or the federal Constitution.