Over the last decade, federal Endangered Species Act (ESA) regulations have swung wildly from one administration to the next. In November 2025, the Fish and Wildlife Service (the Service) and National Marine Fisheries Service announced the fourth such swing, proposing to amend four ESA rules. But this time may be different due to the Supreme Court’s decision in Loper Bright, which overturned the deference doctrine that encouraged federal agencies to take big swings in interpreting statutes to advance political priorities.
Going forward, agencies must defend their rules under the best reading of the statute, with no thumb on the scale in their favor. The Service’s proposed recission of its rule that by default gives to threatened species protections the ESA gives automatically only to endangered species is a good example of how agencies are responding to the new dynamic. Indeed, the proposed rule (like three of the four rules the agencies proposed in November) specifically invokes Loper Bright and concludes that the prior rule is not the best reading of the statute. If courts agree with the Service, a future administration will likely be unable to reinstate the rule.
Read the full essay from the American Bar Association’s magazine, Trends.
