Presidential Discretion and the Endangered Species Act: How Shifting Executive Priorities Shape Regulations and Delistings

Writer: Sofia Peralta

Article Editor: Laney Williams

Associate Editor: Kara Crowther

I. The Endangered Species Act and Its Structural Ambiguity

Designed by Congress to halt and reverse the trend toward species extinction at “whatever the cost,” the Endangered Species Act of 1973 (ESA) is widely regarded as one of the most comprehensive wildlife statutes ever enacted by any nation.¹ The statute aimed to ground conservation decisions in strict biological and scientific criteria rather than political whim. This effort is best illustrated by the inclusion of scientific triggers. The Secretary of the Interior must base species listing determinations “solely on the basis of the best scientific and commercial data available.”² Additionally, Section 9 defines what it means to “take” a listed species with broad terms such as “harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect.”³ This expansive definition ensures that the ESA’s protections extend beyond direct acts of killing or capturing wildlife to encompass a broader range of conduct that could threaten a listed species.⁴

However, the architecture of the act is not as ironclad as it may seem. Congress left several operative terms undefined, including what actions constitute “harm” or whether threatened species receive endangered-level protections by default.⁵ Babbitt v. Sweet Home Chapter of Communities for a Great Oregon (1995) exemplifies the consequences of this ambiguity.⁶ While the United States Supreme Court upheld the Fish and Wildlife Service’s broad definition of “harm” that included habitat modification that kills or injures wildlife, Justice Scalia’s dissent proposed a narrower interpretation.⁷ Scalia contended that “harm” should be limited to affirmative conduct that is intentionally directed against particular animals. This disagreement illustrates how the ESA’s ambiguity can shape debates over the scope of agency authority and species protection.⁸ Recent administrations have used rulemaking and executive orders to reinterpret the ESA’s key terms in ways Congress did not clearly authorize.⁹ If the ESA is to survive as a stable, science-based statute, federal courts must step in and put real limits on this executive power.

II. The Regulatory Pendulum of Recent Administrations

The clearest illustration of this dynamic can be seen in the transformation of the Fish and Wildlife Service’s “blanket rule” of 1975. This rule automatically extended many of the protections already afforded to endangered species to threatened species that were not otherwise dictated under a specific rule by the Service.¹⁰ In 2019, the Trump administration repealed this blanket rule for newly listed species and narrowed the critical-habitat designation process.¹¹ The scope of interagency consultation was also restricted, allowing for new “general regulations” under ESA without undertaking Section 7 consultation.¹² Section 7 requires federal agencies to consult with the Services to ensure their actions are not likely to jeopardize listed species or destroy or adversely modify critical habitat.¹³ In 2024, the Biden administration reversed course, restoring the blanket rule and the pre-2019 consultation framework.¹⁴ In November of 2025, the Trump administration proposed a repeal of the blanket rule for a second time, and by July of 2026, the regulatory definition of “harm” was removed altogether, effectively eliminating habitat modification as a basis for liability under Section 9.¹⁵ The Services justified this rescission by invoking Loper Bright Enterprises v. Raimondo (2024), arguing that the dissenting opinion in Babbitt was more reflective of the statute’s meaning.¹⁶ The Trump administration cited the Loper Bright v. Raimondo ruling to justify its revised interpretations of the agency’s purpose. The administration’s reinterpretation of the ESA extends beyond rulemaking and statutory definitions. In September 2026, President Trump signed an executive order directing the Secretary of the Interior to determine whether the Mexican gray wolf meets the statutory criteria for recovery and delisting within just ninety days.¹⁷ As a result, in just seven years, three successive administrations have interpreted the same law in three different ways, each framed as an effort to restore the ESA’s alleged plain meaning. Such rapid reversals illustrate the need for an objective, fixed legal framework to define the ESA’s operative terms.

III. Executive Discretion, Judicial Review, and the Future of Species Protection

This political whirlwind has not gone unchallenged. In April 2026, environmental groups represented by Earthjustice sued the Trump administration, alleging that it abused the ESA’s exemption power.¹⁸ That power lets the interagency Endangered Species Committee exempt a federal action from ESA compliance in extraordinary circumstances.¹⁹ The plaintiffs allege the administration used it to exempt all of Gulf of America’s oil and gas activity from the Act’s requirements.²⁰ Healthy Gulf v. Burgum will crucially test how far a presidential administration can stretch an emergency loophole to enable industry-wide deregulation.

The legal backdrop for these challenges has been dramatically altered by Loper Bright Enterprises v. Raimondo’s rejection of Chevron deference, which had required courts to defer to reasonable agency interpretations of ambiguous statutes.²¹ In theory, returning interpretive authority to courts should narrow the possibility for executive reinterpretation. In practice, however, the rescission of the definition of “harm” and the justification of the new critical-habitat designation processes suggest the opposite. The Services have used Loper Bright to abandon the interpretation of “harm” that the Supreme Court had previously upheld in Babbitt.²² Rather than reducing executive influence over the ESA, this strategy moves the fight over statutory meaning from rulemaking into federal court, where agencies and challengers will argue over whether the best reading of “harm” includes habitat modification.²³

Moving forward, courts should not allow Loper Bright v. Raimondo to reset the precedent set by Babbitt v. Sweet Home, where the Supreme Court carefully considered the express text and original intent of the Endangered Species Act. While the ESA’s text has remained unchanged since 1973, environmental protections have fluctuated along with each presidential administration. If an administration or executive agency seeks to change settled environmental law, it ought to do so by encouraging Congressional legislation rather than attempting to redefine it.

1. Tennessee Valley Authority v. Hill, 437 U.S. 153, 184 (1978). ↩︎
2. 16 U.S.C. § 1533(b)(1)(A) (2018). ↩︎
3. 16 U.S.C. § 1532(19) (2018). ↩︎
4. 16 U.S.C. § 1538(a)(1)(B) (2018). ↩︎
5. 16 U.S.C. § 1532(19) (2018); 16 U.S.C. § 1533(d) (2018). ↩︎
6. Babbitt v. Sweet Home Chapter of Cmtys. for a Great Or., 515 U.S. 687 (1995). ↩︎
7. Id. at 690–91, 708. ↩︎
8. Id. at 719–20 (Scalia, J., dissenting). ↩︎
9. Endangered Species Act Regulations, Harv. L. Sch. Env’t & Energy L. Program (Sept. 2026), [https://perma.cc/GL2Q-UTZZ]. ↩︎
10. Endangered and Threatened Wildlife and Plants; Regulations Pertaining to Endangered and Threatened Wildlife and Plants, 91 Fed. Reg. 45723 (July 2026). ↩︎
11. Endangered and Threatened Wildlife and Plants; Regulations for Prohibitions to Threatened Wildlife and Plants, 84 Fed. Reg. 44753 (2019). ↩︎
12. Id. ↩︎
13. 16 U.S.C. § 1536(a)(2) (2018). ↩︎
14. Endangered and Threatened Wildlife and Plants; Regulations Pertaining to Endangered and Threatened Wildlife and Plants, 89 Fed. Reg. 23919 (2024). ↩︎
15. Endangered and Threatened Wildlife and Plants; Regulations Pertaining to Endangered and Threatened Wildlife and Plants, 90 Fed. Reg. 52587, 52588 (2025); Rescinding the Definition of “Harm” Under the Endangered Species Act, 91 Fed. Reg. 43300 (2026). ↩︎
16. Loper Bright Enters. v. Raimondo, 603 U.S. 369, 114 (2024). ↩︎
17. Exec. Order No. 14425, 91 Fed. Reg. 57765 (2026). ↩︎
18. Earthjustice, Gulf & Environmental Groups Sue Trump Administration Over Decision to Exempt All Gulf Oil-and-Gas Activities from Endangered Species Act (Apr. 2026), [https://perma.cc/4JMD-M5WM]. ↩︎
19. 16 U.S.C. § 1536(e)–(h), (j) (2018). ↩︎
20. Am. Compl., Healthy Gulf v. Burgum, No. 1:26-cv-01118, (D.D.C. April 2, 2026). ↩︎
21. Loper Bright Enters. v. Raimondo, 603 U.S. 369, 400, 412 (2024). ↩︎
22. The State Energy & Environmental Impact Center, Sixteen AGs Commented to Oppose Proposed Rule to Weaken Endangered Species Act Protections (May 2025), [https://perma.cc/9Z37-ZVNL]. ↩︎
23. Endangered Species Act Regulations, Harv. L. Sch. Env’t & Energy L. Program (July 2026), [https://perma.cc/GL2Q-UTZZ]. ↩︎