The stakes were high in this week’s "oral arguments" in front of the Supreme Court. Republican attorneys general and coal companies argued the court should strip the EPA of its authority to regulate planet-warming gas emissions from power plants. Environmentalists were pessimistic that a 6-3 conservative majority would side with the Biden Administration. Still, during oral arguments for West Virginia v. EPA, which lasted about two hours, not all of the court's conservative majority appeared to be entirely in agreement with the petitioners, though some seemed enamored of the idea that Congress was the proper institution to set emissions policy.

Why This Matters

An eventual ruling restricting EPA authority could hobble the Administration's ability to curb a quarter of US greenhouse gas (GHG) emissions that come from the power sector. It would be a big blow to an Administration that could face an anti-climate Congress starting next year, leaving regulation the best option to effect change.

Legal Doctrine Under the Microscope

The Justices' questions focused on the scope of the Clean Air Act, which gives the EPA authority to regulate air pollution and the Major Questions Doctrine, which states that significant questions must be decided by Congress.

Mindful of her conservative audience, US Solicitor General Elizabeth Prelogar argued the case should be dismissed because there is no federal regulation for power plants on the books right now, a purposefully narrow and technocratic argument. The three liberal justices on the court emphasized how big a shift it would be to strip the EPA's authority preemptively.

Hope From Unlikely Allies

Trump appointee Amy Coney Barrett pointed out that unlike past cases where there's been a legitimate question of whether an agency is operating outside of its boundaries, the EPA is indeed charged with regulating GHG emissions, twice reaffirmed by the Supreme Court.

Justice Clarence Thomas seemed skeptical about the arguments that power companies should only have to retrofit their plants to lower emissions "inside the fence" -- including coal scrubbers or carbon capture -- rather than pushing them to add cleaner sources of energy.

The Other Conservatives

Bush II Appointee Samuel Alito questioned whether considering the impacts of climate change could mean the EPA is almost omnipotent, even asking whether the agency could regulate emissions from single-family homes. Justice Kavanaugh, who as a federal judge had a track record of striking down environmental legislation and regulation, was uncharacteristically quiet, as was Chief Justice Roberts, another jurist feared by the environmental community.