For decades, presidents of both parties and the Supreme Court have agreed that federal law prevents developers from destroying habitat critical to vulnerable wildlife. The Trump administration is now making the case that a landmark Supreme Court ruling ending judicial deference to federal agencies gives it room to reverse that longstanding interpretation.
The problem: Many environmental lawyers say the high court’s 2024 decision doesn’t go nearly that far. If they’re right, one of the administration’s biggest efforts to narrow the Endangered Species Act could face an uphill battle in court.
“There will be a bitter fight over this rule in the courts,” said Ben Cowan, an environmental attorney at the firm Troutman Pepper Locke.
Earlier this month, the Fish and Wildlife Service and NOAA Fisheries finalized a rule that said the agencies will no longer define “harm” of protected plants and animals to include habitat changes that could be detrimental to a species’ survival. The rule change upends an approach that has been the law of the land since the Supreme Court decided in 1995 that federal regulators reasonably included habitat protections in safeguards for two vulnerable birds.
As the impetus for its new rule change, the Trump administration cited the Supreme Court’s 2024 ruling in Loper Bright Enterprises v. Raimondo, which ended Chevron deference. That practice refers to the high court’s 1984 ruling in Chevron v. Natural Resources Defense Council, which concluded that courts should defer to agencies’ reasonable interpretations of laws like the ESA when the wording is ambiguous.
Following Loper Bright, FWS and NOAA Fisheries wrote this month, the question that matters is: “does the agency’s regulation match the single, best meaning of the statute?”
Concluding it did not, the agencies said that the Supreme Court in Loper Bright had left them an opening: “the Court left open the possibility that the executive branch could itself depart from regulations that do not match the single, best meaning of the statute — so long as the new regulations reflect that best meaning.”
The Trump administration has advanced that argument in other contexts, too. In April 2025, a presidential memorandum asked agencies to review their regulations to examine whether they still held up in a post-Loper Bright world.
Federal courts have already found that there are limits to the Trump administration’s approach.
A Washington federal appeals court last month upheld a Biden-era rule strengthening the national particulate matter standard — even after the Trump EPA switched sides in the case to align with the agency’s challengers, claimed it had made a legal error and asked the court to use Loper Bright to kill the Biden standard.
Kevin Minoli, a former career attorney at EPA who served as acting general counsel in Trump’s first term and is now a partner at Alston & Bird, said some people misunderstand Loper Bright to mean that if there is uncertainty in the law, an agency’s authority to regulate is heavily restricted.
“Statutory ambiguities will continue to exist and now instead of the court deferring to the agency interpretation on how to fill that gap, the court is going to give its own interpretation,” Minoli said after the EPA ruling. “There are going to be times when that resolution is in favor of regulation or allowing an agency to regulate as opposed to restricting the agency’s ability to regulate.”
In their ESA rule change, FWS and NOAA Fisheries have done exactly what Loper Bright said is not the job of a federal agency, said Jane Davenport, a senior attorney with Defenders of Wildlife, which is suing the administration over the new regulation.
“Loper Bright said it’s the court’s job, not the agency’s job,” she said.
In the 2024 ruling, Chief Justice John Roberts said that Loper Bright did not “call into question prior cases that relied on the Chevron framework.”
But Jeffrey McCoy, a senior attorney at the conservative Pacific Legal Foundation, said that the case gave agencies an opening to “go back and relook at old definitions.” He also said Loper Bright left open questions about the scope of respect for precedent that relied heavily on Chevron deference.
“This kind of falls in that middle ground of where the Chevron [respect for precedent] lands,” McCoy said.
Back in its 1995 ruling in Babbitt v. Sweet Home, the Supreme Court reviewed the agencies’ definition of “harm.” Though the court cited Chevron, the 6-3 ruling written by Justice John Paul Stevens also did its own analysis, citing dictionary definitions of harm and other interpretations.
“They didn’t just defer to the agency; it’s a very thorough opinion,” Delcianna Winders, director of the Animal Law and Policy Institute at the Vermont Law and Graduate School, said of Sweet Home. “For the administration to say that that opinion no longer carries any weight is specious at best.”
In a footnote in their new ESA rule, FWS and NOAA Fisheries wrote that they disagreed that Sweet Home was “not a Chevron case” and argued the analysis did not “preclude” them from taking the actions they took this month.
Last week, an Interior spokesperson said that the agencies’ role is to “faithfully implement the Endangered Species Act as written, not to expand its reach through interpretations favored by advocacy organizations.”
“The Department will vigorously defend its authority to implement the law according to its plain text,” the spokesperson said.
The rule change itself promises to be a boon for industry by cutting away requirements ranging from the need for incidental take permits in many instances to limits on logging or drilling projects.
In the long-term, though, it may mean uncertainty for businesses — especially if the rule is tied up in court.
“We don’t really know how this is going to be enforced,” said Cowan, the attorney at Troutman Pepper Locke, who often represents renewable energy developers. He said the new interpretation of “harm” promises to become another policy “yo-yo” that changes depending on who is in the White House.
“If that deregulation is unpredictable and just results in a constantly changing regulatory regime,” Cowan said, “it doesn’t help.”
Alex Guillén contributed to this report.
