Since January, the Trump administration has repeatedly gone after the ESA. The argument: Strict rules hamper development and impede “energy domination.” Orders this year have directed agencies to rewrite ESA regulations in ways that could speed up fossil fuel projects while sidestepping required environmental reviews.

Burgum and other conservatives argue the law doesn’t work because its rules are too rigid to do much to spur recovery. Scientists and legal experts say that’s not true, and that the real problem is chronic underfunding and political fickleness.

“We continue to wait until species are in dire straits before we protect them,” said David Wilcove, a professor of ecology and evolutionary biology at Princeton University. “That makes recovery far more difficult and expensive.”

Experts point out that while the ESA isn’t perfect, it has worked to prevent species from disappearing. Since 1973, only 26 species on the list have been confirmed extinct under federal jurisdiction. At least 47 other species are considered lost while still awaiting a listing decision.

“The ESA works more like a critical care unit than a hotel,” Wilcove said. “It’s as though we built a great hospital but never funded enough doctors or equipment.”

One of the ESA’s most notable success stories is the bald eagle. After habitat loss and the pesticide DDT left only a few hundred nesting pairs in the lower 48 states in the 1960s, numbers began to climb after DDT was banned and the eagle gained ESA protections in 1978. By 2007, the bald eagle was delisted as nearly 10,000 pairs were thriving nationwide.

The American alligator and Steller sea lion are two other examples of species that have come back from the brink of extinction thanks to focused protections.

The ESA applies to both public and private property, and that has long been a source of conflict. More than two-thirds of the species on the list depend at least partly on private lands, and about 10 percent are found only on such properties.

“Your ability to use that land is going to be limited and you can be prosecuted,” said Jonathan Adler, a professor of environmental law at the William & Mary Law School. “That discourages landowners from cooperating.”

Studies have shown those rules can create “perverse incentives.” For instance, research on the red-cockaded woodpecker, a bird found in the Southeast, found timber was harvested early in places where the bird lived, likely to avoid federal habitat restrictions that come with ESA listing.

Congress has worked to add incentives over the years, including tax breaks and conservation easements that compensate landowners for conservation efforts. But programs like those have declined in recent years, to the chagrin of many conservationists.

The Endangered Species Act used to have bipartisan support, but has become one of the most litigated environmental laws in U.S. history. Multiple administrations have taken steps to weaken it only to reverse course when a new administration took over.

Now, experts worry the Trump administration’s aggressive stripping away of protections, combined with a conservative-leaning Supreme Court, could create permanent barriers. Meanwhile, climate change and habitat loss are only increasing pressure on more species.

Andrew Mergen, an assistant law professor at Harvard Law School who spent 20 years litigating ESA cases in federal courts for the Justice Department and as part of a now-defunct nonprofit, believes the solution isn’t deregulation but resources. “The law has prevented extinctions,” he said. “The real challenge is committing enough funding and political will to help these species recover, not dismantling the protections that keep them alive.”

Amid the political fighting over the ESA, the last few months have offered a glimmer of hope. In July, the U.S. Fish and Wildlife Service announced that the Roanoke logperch, a freshwater fish found in the East, has recovered enough to come off the endangered list. Burgum pointed to the decision as “proof” the ESA is no longer a “Hotel California.”

But conservationists caution the recovery took more than three decades of dam removals, wetland restoration and costly reintroduction efforts. Many of those initiatives were put in place long before Trump entered the White House.

“The optimistic part,” Wilcove said, “is that we know how to save species when we invest in them. The question is whether we’ll make that commitment.”