Next month, the Supreme Court will hear oral arguments in a case involving an Obama-era power-plant rule that’s no longer in effect, and never really was. The Court has agreed to hear so many high-profile cases this term, on subjects ranging from abortion to gun rights to vaccine mandates, that this one—West Virginia v. Environmental Protection Agency—has received relatively little attention beyond legal circles. But its potential ramifications are profound. At a minimum, the Court’s ruling on the case is likely to make it difficult for the Biden Administration to curtail greenhouse-gas emissions. The ruling could also go much further and hobble the Administration’s efforts to protect the environment and public health.

West Virginia v. E.P.A. “could well become one of the most significant environmental law cases of all time,” Jonathan H. Adler, a law professor at […]