The Trump administration has already targeted the ESA multiple times, in attempts to roll back protections. Critics argue that the ESA’s strict regulations can limit development and prevent the “energy domination” that President Trump has promised to bring to the United States. So far this year, Trump has issued two executive orders instructing federal agencies to review ESA regulations in a way that would fast-track fossil fuel development and circumvent normal environmental reviews.

Conservatives like Burgum often characterize the law as ineffective, with rigid rules that do little to encourage actual recovery. But scientists and legal experts say that’s not because of any flaw in the ESA—it’s because the ESA has been persistently underfunded, and support for it has wavered with each change in political leadership.

“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.”

The ESA can and does prevent species from going extinct—but that’s not as newsworthy as when a species rebounds. Scientists say that’s one reason public attention for the ESA can be episodic. Since 1973, just 26 species on the federal list have gone extinct, but at least 47 others are believed to have gone extinct while still awaiting a listing.

“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.”

The bald eagle is one of the ESA’s marquee success stories. In the 1960s, habitat loss and the pesticide DDT left the species with only a few hundred nesting pairs in the lower 48 states. After DDT was banned, and the eagle gained ESA protections in 1978, numbers began to recover. By 2007, it was removed from the list, with more than 9,800 pairs nesting nationwide.

American alligators and Steller sea lions are among several other species that have come back thanks to protections targeted to their needs.

The ESA’s coverage of both public and private property is also a major source of contention. Congress gave the ESA blanket authority to protect species and their habitats on private land, and those rules have long been a political flashpoint. More than two-thirds of listed species are found on private land, and 10 percent are found only on private land.

“When the government says it’s protecting a species under the ESA, your ability to use that land is going to be limited, and you can be prosecuted,” said Jonathan Adler, an environmental law professor at William & Mary. “That discourages landowners from cooperating.”

Conservation experts point to studies that say those rules create “perverse incentives.” In one review of timber harvests where the red-cockaded woodpecker was present, researchers found that timber was cut earlier, in a practice referred to as “logging the cock.” The theory is that timber companies wanted to cut wood sooner rather than face federal habitat restrictions.

Congress has over the years created incentives for landowners to work with conservation agencies, including tax breaks and conservation easements, which offer landowners compensation for protecting habitats on their properties. Still, such programs have waned in recent years, and conservationists are concerned that those efforts need to be ramped up.

The ESA used to be largely bipartisan but is now one of the most litigated environmental laws in the country. Changes to weaken the law have been made under Republican and Democratic administrations, but have tended to be reversed by the next.

Advocates fear that under a new conservative Supreme Court, the Trump administration’s aggressive changes—combined with a court that has shown hostility to expansive environmental regulations—could permanently hobble the ESA. At the same time, habitat loss, climate change, and a variety of other factors are continuing to push more species toward the brink.

Andrew Mergen, who worked for three decades at the Interior Department litigating ESA cases before joining the faculty at Harvard Law School, said the solution is to focus on resources, not deregulation. “The law has already proven that it can prevent extinctions,” he said. “The real challenge is committing enough funding and political will to help species recover, not dismantling the protections that keep them alive.”

Politics aside, recent events have also given a glimpse of what’s possible. In July, federal biologists announced that the Roanoke logperch, a freshwater fish, has recovered enough to be removed from the endangered list. Burgum used the news as “proof” that the ESA is no longer a “Hotel California.”

But conservationists caution that it took more than three decades of dam removals, wetland restoration, and other, expensive reintroduction efforts to bring the species back from the brink. Those programs were launched decades ago, long before the Trump administration came to power.

“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.”