The ESA has faced renewed criticism since January, with the Trump administration repeatedly targeting the law over its requirement for strict regulations, which officials say hinder development and the promised “energy domination.” The administration has also signed executive orders this year that instruct federal agencies to rewrite ESA rules in a way that would allow for fossil fuel projects to bypass the types of environmental reviews that are typical under the act.

Conservatives like Burgum argue the law’s regulations do more to enshrine stagnation than recovery, pointing to the limited number of species that have come off of the endangered list as the ESA approaches its 50th anniversary.

Scientists and legal experts say, however, that the ESA’s problems aren’t regulatory. Rather, those who have worked with the ESA say it’s been hamstrung by decades of underfunding and political volatility.

“The problem with the ESA is that 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 Record of Prevention, Not Just Recovery

Conservationists and biologists have long argued that while the ESA is imperfect, the bigger problem is that it’s not given the support it needs. Since 1973, only 26 species under federal jurisdiction have gone extinct while on the list, with at least 47 species going extinct after they had been petitioned for listing but not yet added to the list.

“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’s Comeback

Perhaps the most well-known example of the ESA’s success is the recovery of the bald eagle. In the 1960s, the nation’s iconic bird had suffered from the widespread use of the pesticide DDT and habitat loss and degradation. After the chemical was banned and the bird received ESA protections in 1978, numbers began to climb. The bald eagle was officially removed from the endangered list in 2007, with nearly 10,000 nesting pairs in the lower 48 states.

American alligators, Pacific river otters, Steller sea lions, and Florida manatees are other examples of species that have seen significant rebounds under targeted protections.

Challenges on Private Lands

One thing that separates the ESA from other environmental laws is that it provides protections both on public and private lands. This has been one of the more contentious aspects of the ESA, as conservationists have long fought to give species on private property the same protections as those on public lands.

The challenge for species on private lands is that the ESA could limit or place new rules on how the land is used. In the most extreme cases, those restrictions could be considered criminal violations.

“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.”

A number of studies have suggested that landowners have faced “perverse incentives” when it comes to endangered species. One study on red-cockaded woodpeckers, a tree-dwelling bird found in the southeast, found timber was logged earlier in the lifespan of trees in areas where the woodpecker was found, likely so as to avoid future habitat restrictions from the federal government.

In recent years, Congress has taken steps to offer incentives like tax breaks and conservation easements to landowners that protect habitats, but programs have all but disappeared in recent years.

The Endangered Species Act used to enjoy broad bipartisan support, but it’s now one of the most litigated environmental laws in the country. Several administrations have moved to weaken the act in some way, only to have their efforts reversed after a change in party.

Today, there are fears that the Trump administration’s hardline approach to cutting federal protections for endangered species, combined with a conservative-leaning Supreme Court, could be used to permanently shrink the ESA’s power. In the meantime, a changing climate and habitat loss due to development and pollution continue to move more species into crisis levels.

Andrew Mergen, a clinical professor of law at Harvard Law School who worked on ESA cases for two decades with the Department of Justice, said he agreed with Burgum that the ESA needs a bigger focus on recovery, but he argued that the solution is more resources, not deregulation.

“The law has prevented extinctions,” Mergen said. “The real challenge is committing enough funding and political will to make recovery work, not dismantling the protections that keep species from going extinct.”

A Glimpse of Hope

But even as the law is again facing fights in Congress, there have been recent signs of hope. In July, the U.S. Fish and Wildlife Service announced that the Roanoke logperch, an endangered freshwater fish, had been removed from the endangered list for recovering enough to avert extinction. Burgum lauded the decision as a sign that the ESA had finally escaped “Hotel California.”

The catch for many conservationists is that the fish’s recovery took more than three decades, multiple dam removals, wetland restorations, and expensive reintroduction efforts that were launched well before the Trump administration. Still, the recent success may be a sign of what’s possible if the ESA gets the resources it needs.

“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.”