The ESA is facing an existential threat. Since taking office in January, the Trump administration has issued a series of executive orders and agency memos aimed at making it easier for developers to work around the ESA and its strictures, which they say have hamstrung development and kept the U.S. from achieving “energy domination.” The orders direct federal agencies to rewrite ESA regulations in a way that could expedite fossil fuel projects without the standard environmental reviews.

Others conservatives, including Burgum, have argued the law is broken because its inflexible rules have done little to actually recover species. Scientists and legal experts push back that ESA is not the problem—its ineffective because it’s perennially underfunded and has suffered from lack of political will.

“We continue to wait until species are in dire straits before we protect them,” David Wilcove, an ecology professor at Princeton University, told Mother Jones. “That makes recovery far more difficult and expensive.”

A Record of Prevention, Not Just Recovery

The law’s supporters stress that while the ESA has its limits, it’s also a crucial backstop that’s helped prevent mass extinctions. To date, only 26 species have been allowed to go extinct under federal protection since 1973. At least 47 other listed species, by comparison, are believed to have already gone extinct while waiting for a decision on 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 most famous ESA success story: the bald eagle. In the 1960s, a combination of habitat loss and pesticide DDT had reduced nesting pairs in the lower 48 states to just a few hundred. After DDT was banned and the bald eagle was given ESA protections in 1978, its numbers slowly but steadily rebounded. In 2007, the bird was removed from the list; there are now close to 10,000 nesting pairs across the country.

Similar rebounds can be seen in other species such as the American alligator and Steller sea lion, which have also benefited from targeted protections.

Challenges on Private Lands

The ESA’s protections apply not just to public lands but private property as well, which has long been a point of contention. More than two-thirds of listed species are found primarily on private lands and about 10 percent depend on it exclusively.

“If the endangered species happen to be on your land, your ability to use that land is going to be limited and you can be prosecuted,” Jonathan Adler, an environmental law professor at William & Mary, told Mother Jones. “That discourages landowners from cooperating.”

A number of studies have identified “perverse incentives” for landowners to preemptively “shoot and grill” rather than work around new rules. One study published in Science found, for example, that timber was more likely to be cut in the early years of a red-cockaded woodpecker study area than late on, “suggesting that timber companies were more likely to harvest the woodpecker habitat early to avoid a federal listing.”

To incentivize private landowners, Congress created a patchwork of tax breaks and conservation easements, which provide economic compensation for landowners who take steps to protect habitats. But those programs have been declining over the years.

The Future of the ESA

It’s the ESA’s broad powers and ability to restrict landowners’ use of their own property that’s led to so much litigation. Although the ESA enjoyed bipartisan support for much of its history, since the mid-90s it has been “one of the most litigated environmental laws in U.S. history,” according to Adler. In addition to shifting regulations from one administration to the next, efforts to water down the law have come and gone under several presidents but have never led to any long-term reforms.

Now experts fear that combination of the Trump administration’s recent efforts to dramatically rollback protections and a conservative-leaning Supreme Court could narrow the ESA’s reach for years to come, even after the administration leaves. Climate change and habitat loss only make the work more urgent: Species are increasingly pushed to crisis levels more quickly, and data show that the rate of decline of vertebrate populations has not slowed over the past five decades.

Andrew Mergen, a lawyer who spent two decades at the Interior Department litigating ESA cases and now teaches at Harvard Law School, said he’s concerned about those moves. “The most serious challenge the law faces is that its incentives are not sufficient,” he said. “The law has prevented extinctions. The real challenge is committing enough funding and political will to help species recover, not dismantling the few protections that we have in place that are keeping species alive.”

A Glimpse of Hope

In the face of a political battle over the ESA’s future, advocates note the little victories they are still able to accomplish. In July, the U.S. Fish and Wildlife Service released a report on the Roanoke logperch, a freshwater fish found only in a few West Virginia streams, finding that its numbers had stabilized enough to warrant removing it from the endangered list. Burgum cited the announcement as “proof” that the ESA is no longer “Hotel California.”

Conservationists are quick to point out that the fish’s recovery took more than three decades of dam removals, wetland restoration, and a multimillion-dollar reintroduction effort that was decades in the making. Most of the big-ticket dam removals in West Virginia, for example, took place in the early 2000s; the state’s ongoing efforts to reintroduce the fish started in 1985, long before the Trump administration.

“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.”