Clean Power Plan Litigation Update–Court Denies Stay, but Sets Expedited Schedule for Decision

On June 18, 2026, the Federal Energy Regulatory Commission (FERC or the Commission) issued an order to ISO New England Inc. (ISO-NE) directing ISO-NE and ISO-NE participating transmission owners to show cause as to why ISO-NE’s tariff should not be found to be unjust and unreasonable (ISO New England Inc., 195 FERC ¶ 61,215 (2026) (Order)) because it fails to sufficiently:

On June 29, 2026, the Supreme Court granted a petition for certiorari in Leonard Hoffmann v. WBI Energy Transmission, Inc. (Hoffmann), which presents the question whether section 7 of the Natural Gas Act (NGA) requires pipeline companies using federal eminent domain authority to pay landowners’ attorney’s fees in states where landowners can recover those fees under state law. In the decision giving rise to the Supreme Court’s review, the U.S. Court of Appeals for the Eighth Circuit held that a group of ranchers were not entitled to recover their $383,300 in attorney’s fees incurred while negotiating their compensation—creating a circuit split with four other courts of appeals. Hoffmann will be heard during the Court’s October 2026 Term, and marks the second time in five years that the Court has agreed to interpret NGA section 7.

On June 29, 2026, the United States Supreme Court issued Trump v. Slaughter, fundamentally reshaping presidential removal authority over independent regulatory agencies. The decision overruled a 90-year-old precedent established in Humphrey’s Executor v. United States, which had upheld the constitutionality of commissioner removal protections in the Federal Trade Commission Act (FTC Act). As written, the FTC Act permits a commissioner’s removal “only for inefficiency, neglect of duty, or malfeasance in office.” In Slaughter, the Court was asked to reevaluate this standard following the President’s removal of a Democratic-appointed FTC commissioner from office in 2025 without cause. Finding for the President, the Court held that removal was permissible because the FTC Act’s for-cause removal protections for commissioners violate the separation of powers, specifically, the President’s removal power under Article II. The Court explained that the FTC exercises executive power because it promulgates binding rules, investigates and enforces those rules through administrative adjudications, and brings civil enforcement actions in federal court. It found that because it exercises these executive powers, its commissioners “must therefore be controlled by the Chief Executive, in whom such power is vested.” While previous recent cases addressing the scope of the Removal Power, Seila Law LLC v. Consumer Financial Protection Bureau and Collins v. Yellen purported to preserve some kernel of Humphrey’s, the Court made clear that “[i]f anything more is left of Humphrey’s, we overrule it.”

On June 18, 2026, the Federal Energy Regulatory Commission (FERC or the Commission) issued an order to the California Independent System Operator Corporation (CAISO) directing CAISO and CAISO transmission owners to show cause as to why CAISO’s tariff should not be found to be unjust and unreasonable (California Indep. Sys. Operator Corp., 195 FERC ¶ 61,214 (2026) (the Order)) because it fails to sufficiently: