From the beginning of the Trump administration in January, federal officials have repeatedly attacked the ESA. They have argued that onerous rules on private property and government land hinder development and prevent “energy domination.” This year, a series of executive orders told federal agencies to rewrite ESA rules in a way that could expedite fossil fuel development without requiring the environmental reviews otherwise mandated under the law.

Conservatives like Burgum and the GOP-controlled House of Representatives often paint the law as broken, claiming the stringent and sometimes onerous rules do little to further recovery. Scientists and legal scholars point to a different culprit: chronic underfunding and political inconsistency.

“The whole structure is based on this notion that ‘better late than never’ is the right approach,” said David Wilcove, a professor of ecology at Princeton University. “We continue to wait until species are in dire straits before we protect them. That makes recovery far more difficult and expensive.”

For all the criticism of the ESA, legal experts and biologists are quick to point out that the law has averted what would otherwise be mass extinctions. Since 1973, only 26 species under federal protection have gone extinct. At least 47 species, by contrast, are known to have vanished while awaiting a decision on their listing, according to federal data.

“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 may be the law’s most famous success story. A century ago, the national symbol was a common sight across the United States. But a combination of widespread use of the pesticide DDT in the 1960s and the loss of large tracts of habitat left only a few hundred nesting pairs of the bird in the lower 48 states by the late 1970s. After DDT was banned and the bald eagle was granted ESA protections in 1978, numbers gradually increased. In 2007, the bird was taken off the endangered species list, with nearly 10,000 pairs flourishing across the country.

Other successes include the American alligator and the Steller sea lion, which have made strong comebacks since their targeted protections.

The ESA’s Track Record: On Private Land

Because the ESA applies to both public and private lands, tensions between landowners and the federal government have bubbled throughout its history. The Fish and Wildlife Service estimates that more than two-thirds of listed species rely on some degree of private lands for survival, and about 10 percent exist only on such property.

“You’re not going to be able to do what you want with the land,” said Jonathan Adler, a professor of environmental law at William & Mary. “You can be prosecuted for it. That has discouraged a lot of cooperation from landowners.”

Some studies have found that such rules can even create perverse incentives. Research on the red-cockaded woodpecker, for instance, found timber harvesting started early in logging areas with the bird to avoid anticipated habitat restrictions from the federal government.

To address this concern, Congress has created incentives over the years, such as tax breaks and conservation easements that pay landowners to protect critical habitat. Such programs have dwindled in recent years, and many conservationists fear they will not be enough to spur help.

The Endangered Species Act’s Future

For much of its existence, the ESA has enjoyed bipartisan support, at least in theory. But in recent years it has become the most litigated environmental law in U.S. history. While attempts to gut the law were launched by the George W. Bush administration and often halted by Congress when Democrats took control, Trump officials have moved at an unprecedented pace this year alone.

Legal scholars and environmental groups worry that the Trump administration’s unprecedented assault on the ESA, combined with a conservative Supreme Court and a lack of urgency among younger voters, could irreversibly limit the law’s reach. Adding to the urgency is a host of other factors that are driving more species toward critical levels, including climate change and development-driven habitat loss.

Andrew Mergen, a former Fish and Wildlife Service lawyer who spent three decades litigating ESA cases as a lawyer for the ACLU and as a Harvard Law School professor, argues the solution is more resources, not deregulation. The law has “worked extremely well at preventing extinctions,” he said. “The real challenge for our generation is are we willing to put the resources in to help species recover, or are we going to dismantle the protections that prevent them from going extinct.”

Amid all the bickering, one recent announcement shows what can be done. In July, the U.S. Fish and Wildlife Service removed the Roanoke logperch, a freshwater fish, from the endangered species list, saying it has made enough of a recovery to be declared recovered. The announcement was an opportunity for Burgum to crow about the end of “Hotel California.” But conservationists argue the recovery took more than 30 years of dam removals, wetland restorations, and expensive reintroduction efforts that had started long before Trump took office.

“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.”