extinct American birds The U.S. lost a variety of native wildlife in the 20th century, including birds such as (clockwise from top left) Carolina parakeets, dusky seaside sparrows and passenger pigeons. (Photo: James St. John/Flickr, U.S. Fish and Wildlife Service, Seabamirum/Flickr)

The U.S. Endangered Species Act was a bipartisan triumph in 1973, passing Congress by a combined vote of 482-12 before President Richard Nixon signed it into law. Its goal was to prevent further extinctions of American wildlife, protecting species themselves as well as natural habitats for them to inhabit.

Of more than 2,300 total listings under the law — including species, subspecies and distinct population segments — 10 have become extinct since 1973, and eight of those may have died out before receiving protection. That means 99 percent of listed species have so far dodged the fate the law was designed to prevent. According to one analysis, at least 227 listed species would now be extinct if not for the ESA.

After the U.S. lost iconic animals like passenger pigeons, Carolina parakeets and California grizzlies last century, the ESA was a turning point in national relations with native species. The country may not have solved its broader problems with wildlife declines, but a proven ability to halt human-induced extinctions is no small feat.

Nonetheless, the ESA now faces growing scrutiny in Washington, denounced as unfair and unpopular by politicians who want to alter it. This begs a few questions: Is the law working or not? What do scientists say? And what about American voters?

A conservation starter

Red wolf (Canis rufus) A federal proposal would allow hunting of endangered red wolves everywhere but North Carolina's Alligator River National Wildlife Refuge, where about 35 of the wolves currently live. (Photo: Steve Hillebrand/U.S. Fish and Wildlife Service)

Some lawmakers and federal officials are now pushing for significant changes to the 45-year-old law, raising alarm from conservationists about the risks for troubled U.S. wildlife. Recent bills in Congress could make it harder to add species to the list and easier to remove them, as CBS News reports, while other legislation would require the U.S. to consider not only science when deciding whether to list a species, as it does now, but also the potential cost to businesses if the species were protected.

And in the executive branch, the Interior and Commerce departments recently proposed softening several key parts of the ESA, including moves to restrict the designation of critical habitat, to rescind a rule that automatically offers equal protections for threatened and endangered species, and to narrow the definition of "foreseeable future" — since that's when a species must be likely to face danger of extinction if it's going to be granted threatened status, per the ESA.

Efforts like these have simmered for years, mainly among Republican politicians, but as the Washington Post and New York Times both report this month, they're gaining new traction under the Trump administration and a Republican-led Congress.

dusky gopher frog, an endangered species Once common along the U.S. Gulf Coast, the endangered dusky gopher frog vanished from Alabama in 1922 and Louisiana in 1965. It now lives in only two Mississippi counties. (Photo: John A. Tupy/U.S. Department of Agriculture)

Between 1996 and 2010, Congress averaged about five proposals a year to alter the ESA or strip some of its protections, according to an analysis by the Center for Biological Diversity, a nonprofit that advocates for wildlife conservation. There were 30 such bills in 2011, when Republicans took control in the House of Representatives, and roughly 40 per year through 2016, according to the CBD. Since January 2017, Congress has seen at least 75 bills seeking to remove federal protections from specific species or weaken the law overall, the group adds.

One high-profile critic, U.S. Rep. Rob Bishop of Utah, said in 2017 he "would love to invalidate" the law because it has been misused "for control of the land," a sentiment shared by many Republican political figures. That's a pretty serious claim, and one that MNN delved into last year, along with the common complaint that species aren't rebounding quickly enough. But even if such critiques are misleading, as many wildlife biologists and conservationists say, this animus from public servants still presumably reflects a wider distrust of the law among the voters they represent.

Research on public opinion, however, tells a different story.

There ought to be a law

Florida scrub mint, Dicerandra frutescens The endangered scrub mint, native to just one Florida county, is rapidly losing habitat to residential and agricultural development. (Photo: FWS)

In a new study, published July 19 in the journal Conservation Letters, a team of ecologists and social scientists tried to figure out if public support for the ESA has really faded over time, as critics of the law suggest. The researchers gathered data from several sources, including a national survey they conducted in 2014, as well as other published studies and polls spanning two decades since the mid-1990s.

By combining data from all this research, the study's authors found that "support for the Act has been remarkably stable over the past 20 years," they write in an article for The Conversation about their findings. More than four out of five Americans support the ESA, the data show, while only about one in 10 oppose it. The most recent studies were conducted in 2015, 2014 and 2011, yet their results are "statistically indistinguishable" from those of the earliest study, which dates back to 1996.

"In contrast to the often-repeated statement that the Act is controversial," the researchers write, "these data suggest that support for the law among the general population is robust and has remained so for at least two decades."

chart of public opinion on U.S. Endangered Species Act Research shows steady public support for the ESA over 20 years. (Image: Bruskotter, Vucetich, Berardo/The Conversation)

Even in an era when science is routinely politicized, the ESA has retained much of the bipartisan appeal that first buoyed it 45 years ago. The 2014 survey found strong support from both self-identified conservatives (74 percent) and liberals (90 percent), and although the law is more popular with liberals overall, it's still noteworthy that nearly three in four conservatives voiced support for it, versus 15 percent who were opposed. Other sources back this up, the researchers note: 2011 data revealed support from 73 percent of Republicans and 93 percent of Democrats, while a 2015 poll indicates 82 percent of conservatives and 96 percent of liberals like the law.

The ESA's popularity can transcend special interests, too, with 2015 data showing solid support from advocates of agriculture (71 percent) and property rights (69 percent), two interest groups often typecast as critics of the law. (Previous research has found that leaders of interest groups sometimes hold more extreme positions than rank-and-file members, the study's authors point out.)

public support for the U.S. Endangered Species Act, 2015 The ESA enjoys support from an array of interests and ideologies. (Image: Bruskotter, Vucetich, Berardo/The Conversation)

Some supporters of the ESA have advised making concessions to its critics, arguing that gestures of goodwill could help inoculate the law against a larger public backlash. This includes concerns that protections for more polarizing species, such as gray wolves, might breed general resentment of the law over time. The new study also tested that idea, its authors explain, by examining attitudes about the ESA in areas where controversial species have a longer history of federal protection.

People who live near protected wolves showed no more hostility for the ESA than those living far outside wolf country, the study found, nor were they any more likely to distrust the U.S. Fish and Wildlife Service or to dislike wolves themselves. These results "suggest that protecting species — even controversial predators — does not weaken support for protective legislation," the researchers write.

Political protection

Florida bonneted bat pup The endangered Florida bonneted bat exists only in a few counties in South Florida. (Photo: Wikimedia Commons)

The new study depicts a widely popular law, one that appeals to people all over the political, ideological and literal map. The ESA hails from a less polarized time in U.S. history, and its mission of stopping extinctions still seems to resonate across the country. So where is the recent swell of criticism coming from?

"The empirical basis for claims that the ESA is increasingly controversial among the general public is unclear," the researchers write in the study. "This claim appears to emerge from interest groups and influential members of the U.S. Congress who manifest strong opposition to the Act."

The study's authors also point to a 2014 study on U.S. politics, which found that "economic elites" and business-based interest groups wield more influence on policy than "average citizens and mass-based interest groups." And that may help explain why, as the researchers quote from another recent study, "legislators in the U.S. Congress routinely defect from their campaign promises in environmental protection, undermining the link between citizen preferences and policy choice."

That may be discouraging, but it's worth noting that voters can still punish an elected official who defies them — assuming enough of them vote. And despite the petulance in Washington lately, the public support for protecting endangered species offers hope that, like endangered species themselves, bipartisanship isn't extinct just yet.

Most Americans support the Endangered Species Act — but that might not matter
The law is popular with voters, so why do politicians seem to hate it?