Editors' Summary: Federalism has become a highly politicized term in environmental law, with some parties having adopted the term to signify an ideology of devolving federal authority over environmental protection back to the states. In this Article, the author argues that from the states' perspective, the U.S. Supreme Court is using federalism both too much and too little. Too much, in striking down federal law where even the states recognize that a federal role is necessary to address a national problem. Too little, in inappropriately limiting state experimentation. By listening more carefully to the states, the author argues that the Court could transform its federalism jurisprudence from a source of criticism and polarization to a doctrine that should win broad support from across the political spectrum.