In addition to threats to public lands, the Trump administration has repeatedly taken aim at the ESA, saying strict rules impede development and prevent “energy domination.” This year, the president signed executive orders telling federal agencies to rewrite ESA rules to speed fossil fuel projects, sidestepping environmental reviews.

Burgum and other conservatives argue the law is failing, with its strict rules doing little to incentivize recovery. Scientists and legal scholars say the issue is one of chronic underfunding and political whiplash, not the ESA itself.

“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.”

A History of Prevention, Not Just Recovery

Conservationists and scientists note that, despite the failures, the ESA is doing something few experts thought was possible when the law passed in 1973: preventing extinction. Since then, just 26 listed species have gone extinct under federal care, compared with at least 47 species that are believed to have vanished while 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 law’s most famous success is the American bald eagle. Habitat loss and the pesticide DDT left only a few hundred nesting pairs in the lower 48 states by the 1960s. But the eagle was the first animal placed under ESA protections in 1978, and its numbers steadily improved after DDT was banned. By 2007, it was the first species to be delisted, with nearly 10,000 nesting pairs across the country.

Other species, such as the American alligator and Steller sea lion, have also made a strong comeback thanks to protective measures.

Private Lands Challenge Recovery Efforts

A major difference with the ESA is that its protections cover both public and private land, creating a point of contention between agencies and landowners. More than two-thirds of listed species depend on private land for their survival, and about 10 percent are found exclusively on such land.

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

Research has also shown that ESA regulations can cause “perverse incentives,” especially among private landowners. In one study, researchers found that timber was logged early on in forests where the red-cockaded woodpecker lived—presumably to pre-empt federal restrictions on habitat protection.

Congress has tried to provide incentives for landowners to cooperate, such as tax breaks and conservation easements, which pay private owners to protect the habitat. But such efforts have withered in recent years, to the chagrin of conservationists.

What’s Next for the ESA?

Endangered species were once a rare area of bipartisan agreement in Congress. But the ESA has become one of the most litigated environmental laws in American history, with every administration since the 1990s introducing efforts to scale back its reach, only for them to be dismantled under the next administration.

Conservation experts worry that the Trump administration’s fervent undoing of protections, as well as the current makeup of the Supreme Court, could permanently weaken the ESA’s effectiveness. The problem has only gotten worse as climate change and habitat loss have made it more likely that species will hit crisis levels.

Andrew Mergen, who spent 20 years litigating ESA cases as a staff attorney for the Environmental Defense Fund and now teaches at Harvard Law School, said the debate should be about finding resources to fully implement the law, rather than rolling back regulations.

“The law has a proven track record of preventing extinction,” he said. “The real challenge is the lack of political will to invest enough money to help these species recover, not dismantling protections that keep these species on this planet.”