A Supreme Court decision Friday left an uncertain and more difficult path for Congress to shape how the federal government carries out laws on major issues such as environment, health, immigration and more, lawmakers and legal experts said.

The opinion overturned a long-standing legal doctrine called Chevron deference, which required judges to defer to an agency’s interpretation when it comes to regulations about laws that are ambiguous.

Instead, the decision states that judges should give that deference only when Congress explicitly says an agency can make its own decision. The high court ruling will spark more litigation over regulations, experts said, but also scramble the lawmaking process on Capitol Hill.

The Supreme Court’s opinion “supplied no guideposts, not even rough ones, for ascertaining when Congress meant to delegate policymaking authority to the agency,” Nicholas Bagley, a law professor at the University of Michigan, posted on social media.

“The answer is not always going to be clear; Congress may mean to delegate without saying ‘we hereby delegate to the agency,’” Bagley wrote. “Using words like ‘reasonable’ or ‘sufficient’ are clues, for example, and there may be many others.”

Tim Brightbill, a partner at Wiley Rein who specializes in trade law and served as counsel to former Rep. John J. LaFalce, D-N.Y., said the removal of Chevron introduces new complexities to congressional negotiations.

While Democrats may push for greater specificity in the wake of the ruling, Brightbill said, Republicans may prefer broader language “giving courts greater power to rein in the agencies.”

“It depends on the legislation, it depends on who’s in the majority, but there are ways to use the decision to either strengthen or weaken agency regulation,” Brightbill said.

Some Republican lawmakers who sought an end to Chevron for years cheered the decision as an end of federal agencies interpreting laws in ways that Congress didn’t intend.

Sen. Mike Lee, R-Utah, said the court decision represented the first step for Congress to make more decisions when writing laws. In a series of social media posts, Lee said that for decades Congress has made “lazy” laws, frequently pushing off decisions about specifics to agencies rather than making the tough decisions themselves.

“Rather than making laws, Congress has in many instances made … other lawmakers,” Lee said on X, the site formerly known as Twitter.

More difficult

Kaye Pestaina, a vice president at KFF, a health policy organization, on Friday said the ruling could make it more difficult for Congress to pass laws if they have to include the smallest of details in legislation.

Congress often intentionally leaves gaps in legislation for agencies to work out in regulation, Pestaina said. It made it easier for Congress to come to agreements on some complicated issues, but now it could leave agencies vulnerable to lawsuits over regulations implementing those laws.

“You can’t possibly write every technical issue into a statute. It could also make it difficult for legislators to compromise on topics if they need to be more specific and put in more details,” Pestaina said. “And for health care, it’s going to be the consumer that is impacted.”

David Doniger, a senior attorney at the Natural Resources Defense Council, said he was more worried about the ability of Congress to pass laws in the future that could stand up to scrutiny with the new standard laid out by the court.

“For Congress, when it writes these laws, knows that it can’t foresee everything. It can’t get to everything in real time. You’re lucky if Congress visits a statute every 10 years,” Doniger said to reporters Friday.

“So we’re going to see a lot more impediments to effectively protecting us against the kinds of new problems that the world throws at us,” Doniger said. “And there are a lot of those.”

Just getting those new laws written could be a heavy lift, according to J.D. Rackey, a senior policy analyst at the Bipartisan Policy Center and former staff member on the House Select Committee on the Modernization of Congress.

Rackey said Congress doesn’t currently have the staff or technical expertise to write more fine-tuned legislation. Frequently, committees don’t have enough staff or in-depth policy knowledge to write the kind of specific legislation that would survive the scrutiny of the current Supreme Court.

“Even if you want a smaller government, if you want government to do anything, this ruling requires Congress to be much more proscriptive and to have the capacity to do so,” Rackey said. “Outside of the larger policy goals that any one party might have, any future lawmaking is going to be impacted with this decision.”

Rackey pointed out that the House has recently “come around” to the idea that Congress doesn’t have the technical expertise to write rules, and he pointed to the more than 200 recommendations from the select modernization panel he worked on. Many of those have been implemented, he said, but “not enough to reckon with this reality. But it does set the institution on a path to being able to grapple with it.”

The process of writing legislation itself would also get more complicated, Rackey said, as legislators could no longer rely on agencies to make potentially fraught decisions. Getting to final results could mean longer negotiations, more tough votes, more days in Washington and more resources for members and staff.

“I think the level of activity that Congress is going to need to exhibit is going to increase, and I’m not quite sure in the few hours post-decision that they’ve really reckoned with that reality,” Rackey said.

Future actions

Democrats in Congress, the Biden administration and advocates for consumers and environmental organizations criticized the Supreme Court for taking more power for itself.

White House press secretary Karine Jean-Pierre said the decision “takes our country backwards” and undermines the ability of agencies to use their expertise to protect the public.

House Judiciary ranking member Jerrold Nadler, D-N.Y., called the ruling a “power grab” in a statement Friday and argued that Congress should pass legislation (H.R. 1507) to beef up the federal rulemaking process.

In his own statement Friday, Senate Majority Leader Charles E. Schumer, D-N.Y., said Congress had to act to “rein in the outrageous abuses of this brazen Court.”

“In overruling Chevron, the Trump MAGA Supreme Court has once again sided with powerful special interests and giant corporations against the middle class and American families. Their headlong rush to overturn 40 years of precedent and impose their own radical views is appalling,” Schumer said.

House Speaker Mike Johnson, Majority Leader Steve Scalise and Majority Whip Tom Emmer in a statement praised the end of a Chevron doctrine that “led to a massive expansion of the federal government and a reduction of Congress’ role in the policymaking process.”

“Republican committees will be conducting oversight to ensure agencies follow the Court’s ruling and no longer engage in excessive interpretative license in administering statutes under their jurisdiction,” the House GOP leaders said.

Rep. Mark E. Green, R-Tenn., said he would introduce legislation to require the federal government to start sunsetting all agency rules upheld by Chevron unless Congress takes action to uphold them.

“Chevron Deference not only usurps Congress’ lawmaking authority, but gives unelected and unaccountable bureaucrats in Washington enormous control over the lives of Americans. My legislation seeks to right this imbalance and restore Congress and the judiciary to their rightful places in our Constitutional system,” Green said.

Green said Congress needs to “step up its game” and write more clear legislation after Friday’s ruling.

“We can no longer pass the buck when it comes to our legislative duty. We’ve got to be committed to writing clear legislation. Congress has abdicated its role for decades, it’s way past time for that to change,” Green said.

Jessie Hellmann contributed to this report.