Supreme Court Imperils an Array of Federal Rules (2024)

Pinned

The decision is the latest upending longstanding precedents.

The court has now overturned major precedents in each of the last three terms: on abortion in 2022, on affirmative action in 2023 and now on the power of administrative agencies. In a dissenting opinion, Justice Elena Kagan said the ruling amounted to the Supreme Court’s latest judicial power grab. “A rule of judicial humility,” she wrote, “gives way to a rule of judicial hubris.”

Here’s what else to know:

• What is Chevron deference? It is the principle from the Supreme Court’s 1984 ruling that gave regulatory agencies leeway to interpret laws that Congress had left vague. When Congress passes a law, it cannot anticipate all the ways that the economy, the nation and the world will change. If regulators had only the powers that Congress explicitly gave them, many regulations would be vulnerable to legal challenges. The ruling could have broad implications for the regulation of food and drugs, the banking and financial sector, taxation, as well as conservative activists’ targeting of medication abortion and rights for transgender people.

• A major goal of the conservative legal movement: Friday’s ruling undoes a precedent that empowered executive branch agencies, which many conservatives have come to believe are dominated by liberals under both parties’ administrations — a critique often described as “the deep state.” Elizabeth Murrill, the Republican attorney general of Louisiana who has taken a leading role in lawsuits against the Biden administration’s environmental regulations, said Chevron deference had been “wildly abused by this administration more than any other.” Read about conservatives’ view of the precedent.

• The White House reaction: Karine Jean-Pierre, the White House press secretary, said Friday’s decision was the latest example of the Supreme Court siding with Republican-backed special interests to block “common-sense rules that keep us safe, protect our health and environment, safeguard our financial system, and support American consumers and workers.”

• Supporters of regulatory oversight criticized the decision: Critics of the decision said it would empower the courts, not Congress, to dictate policy. “Getting rid of Chevron deference says, you know what? The courts will be the decider of how to interpret these laws instead of experts who are knowledgeable in the field,” said Senator Jeff Merkley, Democrat of Oregon, who sits on the Senate Environment and Public Works Committee.

• The case started with fishermen: The court heard two almost identical cases, Loper Bright Enterprises v. Raimondo, and Relentless v. Department of Commerce. Both cases involved a 1976 federal law that requires herring boats to carry federal observers to collect data used to prevent overfishing.

  Under a 2020 regulation interpreting the law, owners of the boats were required not only to transport the observers but also to pay $700 a day for their oversight. Fishermen in New Jersey and Rhode Island — backed by two conservative organizations that decry the “administrative state” — sued, saying the 1976 law did not authorize the relevant agency, the National Marine Fisheries Service, to impose the fee.

The decision is the latest blow to regulatory agencies.

In recent years, the Republican majority has also made it easier to sue agencies and get their rules struck down, including by advancing the so-called major questions doctrine. Under that idea, courts should nullify economically significant regulations if judges decided Congress was not clear enough in authorizing them.

Advancing and entrenching that idea, the court has struck down an E.P.A. rule aimed at limiting carbon pollution from power plants, and barred the Occupational Safety and Health Administration from telling large employers they must either have their workers vaccinated against the Covid-19 virus or have them undergo frequent testing.

And in a 2020 ruling, the five Republican appointees then on the Supreme Court struck down a provision of the law Congress enacted to create the Consumer Financial Protection Bureau that had protected its head from being fired by a president without a good cause, like misconduct.

Karine Jean-Pierre, the White House press secretary, said Friday’s decision was the latest example of the Supreme Court blocking “common-sense rules that keep us safe, protect our health and environment, safeguard our financial system, and support American consumers and workers.”

The court has not always gone as far as libertarians wanted, however. Earlier this term, the court rejected a challenge to the way the Consumer Financial Protection Bureau is funded. Striking it down would have opened the door to lawsuits to nullify every regulation and enforcement action it has taken in its 13 years of existence, including ones concerning mortgages, credit cards, consumer loans and banking.

While overturning Chevron is now the capstone victory for the conservative legal movement’s assault on the administrative state, it may not be the end of the story. More extreme opponents of regulation hope the court will someday embrace a sweeping version of the so-called nondelegation doctrine.

Under that vision, the Constitution does not allow Congress to delegate any of its legislative authority to executive branch agencies. If so, all regulations should be struck down because the only way society can impose a legally binding rule on business interests is if Congress manages to specifically enact one via statute.

Advertisem*nt

SKIP ADVERTIsem*nT

She said in a statement that President Biden had directed his legal team to work with the Justice Department and other lawyers “to review today’s decision carefully and ensure that our administration is doing everything we can to continue to deploy the extraordinary expertise of the federal workforce to keep Americans safe and ensure communities thrive and prosper.”

The Chevron decision advances that precedent, essentially applying it to all regulations, large and small. Together, experts say that the two rulings could mean that more government regulations are struck down or scaled back by the courts, and that government agencies could be more timid or restrained in writing new rules.

Utah geared up for a fight in anticipation of the court’s ruling.

Sean D. Reyes, the Utah attorney general, has made well known his distaste for the Chevron precedent, which gives federal agencies leeway to interpret laws that Congress left vague. In a news release, he called the standard “one of the greatest threats to individual liberty.”

“For far too long, it has been wielded by big government proponents, unaccountable federal bureaucrats, and activist courts to destroy the freedoms of hard-working Americans and rob local control from our states,” he said in a statement in August.

Mr. Reyes signed on with about two dozen other Republican attorneys general to a friend-of-the-court brief decrying the onus on small businesses, the vast costs and the volume of regulations, which they said vastly outpace the number of laws passed by Congress, though that has been on a downward trend for decades.

Utah is not entirely alone in its war room crouch, said Gary Feldon, an attorney with Hollingsworth who noted Utah’s work in a recent article anticipating the ruling.

“I don’t know that anybody is doing it quite as systemically as the state of Utah seems to be, but industry and businesses are certainly aware that we are on the edge of a major shift,” Mr. Feldon said. “And the savvy among them are making sure that they’re in position to take advantage of it now.”

Advertisem*nt

SKIP ADVERTIsem*nT

The ruling is likely to stymie public health initiatives, experts said.

“We anticipate that today’s ruling will cause significant disruption to publicly funded health insurance programs, to the stability of this country’s health care and food and drug review systems, and to the health and well-being of the patients and consumers we serve,” several of the nation’s largest health organizations, including the American Public Health Association and the American Cancer Society, said in a joint statement on Friday.

Federal officials will feel a “chilling effect” that will slow regulations in areas in which they do not have explicit authority, said Dr. Reshma Ramachandran, co-director of the Yale Collaboration for Regulatory Rigor, Integrity and Transparency, an initiative that studies medical product evaluations and coverage in order to improve patient outcomes.

Instead of hiring more scientific and technological experts, federal agencies will have to arm themselves with lawyers, she predicted.

Zachary L. Baron, director of the Health Policy and the Law Initiative at the O’Neill Institute at Georgetown Law in Washington, said one result of the ruling “is likely to be an increase in litigation and an increase in uncertainty.”

“It seems like, as Justice Kagan wrote in her dissent, the court is flipping the script today, giving more authority to courts and judges and less authority to federal agencies and the expertise that they have,” Mr. Baron said.

Today’s ruling is one in a string of court decisions in recent years in which the court has given itself “more and more power over every significant policy dispute, and closing the door on agency experts that have been working on these issues for years,” he said.

Indeed, Justice Elena Kagan’s dissent offered an example of the type of detailed scientific question judges may now face in court: When does an alpha amino acid polymer qualify as a protein?

“I don’t know many judges who would feel confident resolving that issue,” she wrote. “(First question: What even is an alpha amino acid polymer?)”

The Food and Drug Administration, she added, has scores of experts who could “collaborate with each other on its finer points, and arrive at a sensible answer.”

The Chevron doctrine has its roots in public health: a 1984 Supreme Court case involving air pollution. At issue was the Environmental Protection Agency’s interpretation of an ambiguous provision in the Clean Air Act that affected companies subject to pollution controls.

The court determined that federal agencies should receive “deference” for reasonable interpretations of gaps or ambiguities in the statutes that Congress could not have anticipated when it crafted the laws.

The court gave federal agencies leeway because of their subject matter and scientific expertise, experience and political accountability.

Now that this authority has been curtailed, public health agencies simply may regulate less, a goal long sought by proponents of a smaller federal government and companies eager to pursue unfettered growth.

“If agencies know that everything they do that is not perfectly aligned with a statute will be scrutinized by the court, they will be less likely to promulgate expansive rules or swift rules,” said Selina Coleman, a health care partner at Reed Smith, a large law firm.

Other experts also predicted an explosion in litigation and uncertainty. The ruling will “signal to industry and aggressive state attorneys general to open the floodgates to more litigation to block federal regulatory efforts,” Mr. Baron said.

Moving public health decisions from federal agencies to Congress and the courts will lead to “incoherence, chaos and endless litigation,” said Paul Billings, national senior vice president of public policy at the American Lung Association.

The Supreme Court and lower courts have already chipped away at the authority of regulatory bodies to make public health decisions. Many such rulings were handed down during the coronavirus pandemic.

In November 2021, the Supreme Court upheld an injunction that barred the Centers for Disease Control and Prevention from enforcing a national moratorium on evictions from rental housing, despite fears that a wave of such displacements would exacerbate the spread of Covid-19.

In January 2022, the Supreme Court ruled that the Occupational Safety and Health Administration could not require large businesses to vaccinate their employees against Covid. In April 2022, a federal judge in Florida struck down a C.D.C. mandate that required passengers to wear masks on public buses, trains and planes.

Today’s Supreme Court decision will task Congress with spelling out exactly what agencies like the C.D.C. can and cannot do, several observers said. “Nobody has any confidence that Congress can get its act together to do that,” said Dr. Georges C. Benjamin, executive director of the American Public Health Association.

“I think the decision as written solidifies employment for lawyers and judges, and undermines the authority of experts,” he added.

Other scientists also expressed doubt that Congress or the judiciary could remain abreast of constantly evolving scientific evidence. “To keep up with that pace of change, even for a medical or scientific professional, is very challenging,” said Karen Knudsen, chief executive of the American Cancer Society.

“It’s going to affect everything from airbags in peoples’ cars to the quality of the food they feed their families and the water they drink,” said Stephen Hall, legal director of Better Markets, which pushes for tougher regulation. “This decision threatens to return the United States to the 1910s when the government had very limited ability to protect the health, safety, and welfare of America.”

Advertisem*nt

SKIP ADVERTIsem*nT

The ruling could undermine the Treasury Department and the I.R.S.

“Taxpayers are likely to challenge the validity of dozens of tax regulations and those challenges are much more likely to prevail,” said Robert J. Kovacev, a lawyer at the firm Miller & Chevalier who specializes in tax litigation and represents businesses engaged in disputes with the tax agency. “For years the I.R.S. has issued regulations expanding its power and restricting tax benefits that Congress intended taxpayers to receive.”

The ruling will also present new challenges as the Biden administration rolls out its alternative energy credit regulations, Mr. Kovacev said, because the I.R.S. will not be able to take for granted that courts will defer to its regulations.

The Tax Policy Center said in an analysis last fall that such a Supreme Court decision would make it harder for an agency such as the I.R.S. to write rules to address industries that are quickly evolving, such as cryptocurrencies, and that it would be more difficult to fill in the gaps for Congress when lawmakers rush to write tax legislation.

Critics of the tax agency said on Friday expressed optimism the ruling would limit its powers.

“Today’s decision will level the playing field for taxpayers and government agencies,” said Joe Bishop-Henchman, executive vice president at the National Taxpayers Union Foundation. “Unreasonable I.R.S. interpretations will no longer automatically win in court, which is as it should be, and reasonable interpretations will still have the force of law.”

Treasury Department and the I.R.S. did not immediately have a comment.

Advertisem*nt

SKIP ADVERTIsem*nT

Under that vision, the Constitution does not allow Congress to delegate any of its legislative authority to executive branch agencies. If so, all regulations should be struck down because the only way society can impose a legally binding rule on business interests is if Congress manages to specifically enact one via statute.

Conservative Christian activists see Chevron as major win to push their causes.

They see the decision as a new precedent as they seek to bring a future case against the F.D.A. to the Supreme Court. Ms. Hamrick said such a case was likely to get a better reception “when the F.D.A. is no longer given the benefit of the doubt.”

The Alliance Defending Freedom, the conservative Christian legal advocacy group that argued against the F.D.A.’s approval of the abortion pill and lost, also praised the ruling.

Federal agencies “frequently disrespect Americans’ most cherished principles — including religious freedom and the sanctity of life,” said Julie Marie Blake, senior counsel at A.D.F. “Now, the court has wiped away a major roadblock that prevented Americans from holding government officials accountable.”

A.D.F. had filed an amicus brief in the case on behalf of Christian Employers Alliance, a group that defends freedoms for Christian businesses. The brief criticized a range of federal agencies, including the Department of Education and Health and Human Services, for what it said was the agencies’ efforts on “ending women’s sports” to imposing “radical gender ideology” to “forcing employers to pay for puberty blockers, cross-sex hormones and amputating healthy organs.”

Now, the brief’s argument looks like a road map for what lawyers may want to pursue with Chevron gone.

“For 40 years, Chevron deference has allowed administrative agencies to enact regulations with little accountability,” Beth Milito, Executive Director of NFIB’s Small Business Legal Center, said in a statement. “Abandoning Chevron will hold agencies accountable and level the playing field in court cases between small businesses and administrative agencies.”

Advertisem*nt

SKIP ADVERTIsem*nT

Democrats, anticipating Chevron’s demise, gave E.P.A. more power in recent climate law.

Climate change rules could be particularly vulnerable to legal attack in a post- Chevron world. That’s because the E.P.A. wrote them under the authority of the 1970 Clean Air Act, a sweeping law that directs the agency to regulate all pollutants that endanger human health.

But the legislators of 1970 did not specify anywhere in the law that carbon dioxide emissions, the chief cause of climate change, should be regulated. It doesn’t even mention climate change.

Democrats changed that in the 2022 Inflation Reduction Act, a law chiefly focused on spending billions of dollars on clean energy technology to fight climate change. But the law amends the Clean Air Act to define the carbon dioxide produced by the burning of fossil fuels as an “air pollutant.”

That language, according to legal experts as well as the Democrats who worked it into the legislation, explicitly gives the E.P.A. the authority to regulate greenhouse gases and to use its power to push the adoption of wind, solar and other renewable energy sources.

The specificity of that legal language should protect E.P.A.’s authority to regulate carbon dioxide pollution by limiting their emission from tailpipes and smokestacks.

However, opponents of the rule — chiefly, the fossil fuel industry — are still expected to use the demise of the Chevron doctrine to attempt to weaken the specifics of those rules.

Just yesterday, the majority struck down the ability of agencies to enforce their rules via in-house tribunals before technical-expert administrative judges. Instead, it ruled, agencies must sue accused malefactors in federal court before juries.

In recent years, the Republican majority has also made it easier to sue agencies and get their rules struck down, including by advancing the so-called major questions doctrine. Under that idea, courts should nullify economically significant regulations if judges decided Congress was not clear enough in authorizing them. Advancing and entrenching that idea, the court has struck down an E.P.A. rule aimed at limiting carbon pollution from power plants, and barred the Occupational Safety and Health Administration from telling large employers they must either have their workers vaccinated against the Covid-19 virus or have them undergo frequent testing.

And in a 2020 ruling, the five Republican appointees then on the Supreme Court struck down a provision of the law Congress enacted to create the Consumer Financial Protection Bureau that had protected its head from being fired by a president without a good cause, like misconduct.

The court has not always gone as far as libertarians wanted, however. Earlier this term, the court rejected a challenge to the way the Consumer Financial Protection Bureau is funded. Striking it down would have opened the door to lawsuits to nullify every regulation and enforcement action it has taken in its 13 years of existence, including ones concerning mortgages, credit cards, consumer loans and banking.

Overturning the Chevron decision has been a major goal of the conservative legal movement.

The decision rejecting Chevron threatens regulations covering — just for starters — health care, consumer safety, government benefit programs and climate change.

Chevron — and bear with me here, this will hurt only for a minute — established the principle that courts must defer to agencies’ reasonable interpretations of ambiguous statutes. The theory is that agencies have more expertise than judges, are more accountable to voters and are better able to establish uniform national policies.

“Judges are not experts in the field, and are not part of either political branch of the government,” Justice John Paul Stevens wrote in 1984 for a unanimous court (though three of its justices recused for reasons of health or financial conflict). Justice Stevens later said of the opinion, which was easily his most influential, that it was “simply a restatement of existing law.”

The decision was not much noted when it was issued. “If Chevron amounted to a revolution, it seems almost everyone missed it,” Justice Neil Gorsuch, the harshest critic of the doctrine on the current court, wrote in 2022, saying that courts had read it too broadly.

At first, conservatives believed that empowering agencies would constrain liberal judges. So the Reagan administration, which had interpreted the Clean Air Act to allow looser regulations of emissions, celebrated the decision.

Justice Stevens, rejecting a challenge from environmental groups, wrote that the Environmental Protection Agency’s reading of the statute was “a reasonable construction” that was “entitled to deference.”

The head of the E.P.A. when the regulation was issued? Anne Gorsuch, Justice Gorsuch’s mother.

Most surprisingly, given its current bad odor with the right, Chevron was at least initially championed, celebrated and elevated by Justice Antonin Scalia, a revered conservative figure who died in 2016. “In the long run Chevron will endure and be given its full scope,” he wrote in a law review article in 1989, adding that this was so “because it more accurately reflects the reality of government.”

What, then, accounted for the decision’s place on the conservative hit list? After all, as the case itself demonstrates, it requires deference to agency interpretations under both Republican and Democratic administrations.

The answers are practical, cultural and philosophical. Business groups on the whole remain hostile to regulation. Many conservatives have come to believe that executive agencies are dominated by liberals under both parties’ administrations — the shorthand for this critique is “the deep state.” And some on the right have become hostile to the very idea of expertise.

Advertisem*nt

SKIP ADVERTIsem*nT

The ruling will embolden challenges against financial regulators.

While the decision will complicate regulators’ jobs, its effects will likely seem familiar to them. Losing the Chevron deference will amplify a shift already underway in the lower courts, which have in recent years been receptive to lawsuits challenging financial regulators’ actions. The U.S. Court of Appeals for the Fifth Circuit, in particular — and the federal courts under its purview — has been a major roadblock, preventing the bureau from imposing credit card late fee limits and expanding its interpretation of anti- discrimination laws.

One recent action that may now be ripe for a challenge is the bureau’s decision that Buy Now, Pay Later lenders are credit card providers, giving buyers a right to dispute charges and demand refunds.

“Because this interpretive rule pushes the envelope past existing law into pure agency interpretation, it will be an attractive target for industry challenge,” said Erin Bryan, another partner at Dorsey & Whitney.

In addition to the C.F.P.B., trade groups representing banks have sued other federal bank regulators, including the Office of the Comptroller of the Currency and the Federal Reserve. They have challenged those regulators over a host of rules, from a sweeping anti-redlining regulation to one requiring banks to disclose detailed data about their small business loans.

Outside advocacy groups have also gotten into the habit of suing the regulators, though the bulk of their activity took place during the Trump administration, when proponents of stricter financial regulation felt that government officials were unlawfully loosening rules on banks and other firms. Their preferred appeals circuit was the Ninth; they often filed federal court cases in the Northern District of California, where they expected judges to treat their arguments favorably.

Both sides won rulings by judges who declined to defer to the regulators.

“A court can always avoid getting to the Chevron deference in the first place by saying that a statute is not ambiguous, and that’s what happens the vast majority of the time,” said Randy Benjenk, a partner at Covington & Burling who focuses on financial regulation.

“In practice it’s been rare for a judge to conclude that a statute is ambiguous and defer to an agency’s interpretation of law. Judges routinely reach their own interpretations that contradict the agencies. That’s true in courts nationwide, whether in Texas, California or anywhere else.”

Advertisem*nt

SKIP ADVERTIsem*nT

The oversight of food, drugs and tobacco is expected to be a target.

Challenges could range from whether tainted spinach can be traced back to a farm to the very core of the F.D.A.’s decisions on whether drugs are safe and effective enough to be sold in the United States.

“F.D.A. has always been called the gold standard for product approval throughout the world,” said Perham Gorji, a partner at the law firm DLA Piper and former deputy chief counsel at the F.D.A. “Less deference to F.D.A. is going to obviously change what’s available in terms of products that are available here in the United States.”

The agency employs about 18,000 people, many of whom are doctors or have advanced degrees in biostatistics, chemistry and toxicology. Given the complexity of some scientific decisions the agency makes, attorneys who focus on the F.D.A. said initial challenges might focus on areas in which the F.D.A. exerts policy clout, including some that touch on drug pricing.

Chad Landmon, an attorney with Axinn who leads the F.D.A. practice group, predicted that early lawsuits could stem from a mix of problems companies face.

“I think companies are going to be much more aggressive and generally are going to be looking for opportunities to challenge the F.D.A.,” Mr. Landmon said.

Others expect a broad onslaught from tobacco companies regulated by the agency. “I would expect the tobacco industry to target every aspect of the F.D.A.’s regulatory infrastructure,” said Desmond Jensen of the Public Health Law Center. The agency decides which e-cigarettes are authorized for sale and can reject new cigarettes that could attract new smokers.

Limits on Chevron are widely thought to favor industry, but the reality could be more complex if advocacy groups gear up, said Nick Shipley, a former lobbyist for BIO and PhRMA and the founder of Cronus Consulting. He cited the group that challenged the F.D.A.’s approval of abortion medications.

“Industry,” he said, “could be caught in the crossfire.”

Here’s what the Chevron ruling could mean in everyday terms.

The court’s opinion could make it easier for opponents of federal regulations to challenge them in court, prompting a rush of new litigation, while also injecting uncertainty into businesses and industries.

“If Americans are worried about their drinking water, their health, their retirement account, discrimination on the job, if they fly on a plane, drive a car, if they go outside and breathe the air — all of these day-to-day activities are run through a massive universe of federal agency regulations,” said Lisa Heinzerling, an expert in administrative law at Georgetown University. “And this decision now means that more of those regulations could be struck down by the courts.”

The decision effectively ends a legal precedent known as “Chevron deference,” after a 1984 Supreme Court ruling. That decision held that when Congress passes a law that lacks specificity, courts must give wide leeway to decisions made by the federal agencies charged with implementing that law. The theory was that scientists, economists and other specialists at the agencies have more expertise than judges in determining regulations and that the executive branch is also more accountable to voters.

Since then, thousands of legal decisions have relied on the Chevron doctrine when challenges have been made to regulations stemming from laws like the 1938 Fair Labor Standards Act, the 1970 Clean Air Act, the 2010 Affordable Care Act and others.

In writing laws, Congress has frequently used open-ended directives, such as “ensuring the rule is in the public interest,” leaving it to agency experts to write rules to limit toxic smog, ensure that health plans cover basic medical services, ensure the safety of drugs and cosmetics and protect consumers from risky corporate financial behavior.

But that gave too much power to unelected government officials, according to conservatives, who ran a coordinated, multiyear campaign to end the Chevron doctrine. They believe the courts, not administrative agencies, should have the power to interpret statutes. The effort was led by Republican attorneys general, conservative legal activists and their funders, several with ties to large corporations, and supporters of former President Donald J. Trump.

“Overturning Chevron was a shared goal of the conservative movement and the Trump administration. It was expressed constantly,” said Mandy Gunasekara, who served as chief of staff at the E.P.A. under President Trump and has helped write Project 2025, a policy blueprint for a next Republican administration. “It creates a massive opportunity for these regulations to be challenged. And it could galvanize additional momentum toward reining in the administrative state writ large if the administration changes in November.”

Still, Jonathan Berry, who served as a senior Labor Department official under Mr. Trump, noted that overturning the Chevron doctrine itself “doesn’t immediately blow anything up.”

Rather, Mr. Berry said, the fate of the regulations will be determined by what happens when they start moving through the courts without the protection of Chevron. “The mystery is exactly how much of this stuff goes down,” Mr. Berry said.

Here is a look at how the decision might affect various government agencies.

The Environmental Protection Agency

Environmentalists fear that the end of the Chevron doctrine will mean the elimination of hundreds of E.P.A. rules aimed at limiting air and water pollution, protecting people from toxic chemicals and, especially, tackling climate change.

Over the past six months, the Biden administration has issued the most ambitious rules in the country’s history aimed at cutting climate-warming pollution from cars, trucks, power plants and oil and gas wells. Without those rules, it would very likely be impossible for President Biden to achieve his goal of cutting greenhouse gas emissions in half by the end of the decade, which analysts say all major economies must do to avoid the most deadly and catastrophic impacts of global warming.

All of the Biden climate rules have already been the target of lawsuits that are winding their way through the courts.

Legal experts say that the reversal of Chevron will not remove E.P.A.’s foundational legal obligation to regulate climate-warming pollution: that was explicitly detailed in a 2007 Supreme Court decision and in 2022 legislation passed by Democrats in anticipation of challenges to that authority.

But the specific regulations — such those designed to cut car and truck pollution by accelerating the transition to electric vehicles, or to slash power plant pollution with the use of costly carbon capture and sequestration technology — could now be more legally vulnerable.

The result would quite likely be that stringent climate rules designed to sharply reduce emissions could be replaced by much looser rules that cut far less pollution. Experts say that could also be the fate of existing rules on smog, clean water and hazardous chemicals.

Labor Agencies

The elimination of the Chevron deference could affect workers in a variety of ways, making it harder for the government to enact workplace safety regulations and enforce minimum wage and overtime rules.

One recent example was in April, when the Biden administration raised the salary level below which salaried workers automatically become eligible for time-and-a-half overtime pay, to nearly $59,000 per year from about $35,000, beginning on Jan. 1. Business groups have challenged the Labor Department’s authority to set a so-called salary threshold and such challenges will have far better odds of success without the Chevron precedent, experts said.

The shift could also rein in protections for workers who publicly challenge the policies of their employers, according to Charlotte Garden, a professor of labor law at the University of Minnesota. The National Labor Relations Board often concludes that a single worker has the right to protest low pay or harassment or attendance policies without being disciplined or fired. But the relevant law refers to “concerted activities,” meaning the protection may now apply only to groups of employees who stage such protests, not individuals, Professor Garden said.

Food and Drug Administration

The Food and Drug Administration flexes significant power when it sets the standards for how new drugs must be studied and whether they are safe and effective before they are approved for use. Attorneys who worked at the agency said that companies chafing at that high bar for approvals might now challenge those regulations. Others said legal challenges could ultimately affect drug prices.

Challenges are also expected in the agency’s tobacco division, which authorizes the sale of new cigarettes and e-cigarettes with the intent to protect public health. “I would expect the industry to attack the F.D.A.’s authority to do premarket review at all,” said Desmond Jenson, deputy director of the commercial tobacco control program at the Public Health Law Center.

Others noted the Chevron decision could have a chilling effect, compelling the F.D.A. to proceed quite carefully, given the potential for litigation, if it moves forward with proposals to ban menthol cigarettes or make them less addictive by slashing nicotine levels.

Abortion opponents say the ruling could work in their favor as they seek to bring another case against the Food and Drug Administration’s approval of an abortion medication to the Supreme Court, which rejected their effort to undo the agency’s approval of the drug this month.

Kristi Hamrick, a strategist for Students for Life of America, an anti-abortion organization, said in a statement that such a case was likely to get a better reception “when the F.D.A. is no longer given the benefit of the doubt.”

Health Care

The court’s ruling could affect how Medicare, Medicaid and Affordable Care Act insurance plans are administered, health law experts said, as opponents gain an opportunity to challenge how these huge programs operate.

The health care system is governed by elaborate regulations covering how hospitals operate, what providers are paid for medical services and how insurance companies are monitored by the government. Much of that regulation is grounded in interpretation of laws that date back decades. Major industries could be affected if rules are changed.

“There’s an awful lot of regulation that flies under the radar that’s just about making sure the trains run on time,” said Nicholas Bagley, a law professor at the University of Michigan.

Rachel Sachs, a health law expert at the Washington University School of Law in St. Louis, said that the complex set of rules devised and governed by the Department of Health and Human Services and the Centers for Medicare and Medicaid Services could be challenged in new ways.

“There’s a lot of work to do in that process,” she said. “And therefore there are a lot of opportunities for challengers to pick at specific choices that C.M.S. and H.H.S. are making in the interpretation of these rules.”

The Supreme Court decision will require Congress to specify exactly what agencies like the C.D.C. can and cannot do, several analysts said. “Nobody has any confidence that Congress can get its act together to do that,” said Dr. Georges C. Benjamin, executive director of the American Public Health Association.

“I think the decision as written solidifies employment for lawyers and judges, and undermines the authority of experts,” he added.

Other scientists also expressed doubt that Congress or the judiciary could remain abreast of constantly evolving scientific evidence. “To keep up with that pace of change, even for a medical or scientific professional, is very challenging,” said Karen Knudsen, chief executive of the American Cancer Society.

The Biden administration has written health regulations anticipating a world without the Chevron deference, said Abbe R. Gluck, a health law expert at Yale Law School who served in the White House at the beginning of Mr. Biden’s term. For that reason, she thinks litigation over the most recent rules may be less influenced by this change than challenges concerning some older regulations.

“The Supreme Court has not relied on Chevron in quite a few years,” she said. “So the federal government, including H.H.S., has become accustomed to drafting regulations and making its interpretation arguments as if Chevron did not exist.”

“They’ve already adjusted,” Ms. Gluck said.

Treasury and the Internal Revenue Service

The Treasury Department and the Internal Revenue Service both have broad mandates to interpret legislation when they write rules and regulations and enforce the tax code.

Since the Inflation Reduction Act passed in 2022, the Treasury Department has been racing to roll out regulations related to billions of dollars of clean energy tax credits that provide huge incentives for things such as the manufacturing of batteries or the purchase of electric vehicles. The Treasury Department has received pushback from some lawmakers who contend that it has not followed the intent of the law.

Although Congress creates the tax code through legislation, the I.R.S. has wide latitude in how the tax laws are administered. Accounting experts have suggested that the court’s ruling could complicate the agency’s ability to administer the tax code without specific direction from Congress.

A recent example is how the agency last year delayed enforcement of a contentious tax policy that would require users of digital wallets and e-commerce platforms to report small transactions. The new provision was introduced in the tax code in 2021 but was strongly opposed by lobbyists and small businesses.

The I.R.S. received criticism from some lawmakers for delaying the policy, but the agency defended its decision by arguing that taxpayers needed a longer transition period before the measure should be enforced to avoid a chaotic tax season.

Elizabeth Dias, Teddy Rosenbluth and Roni Rabin contributed reporting.