In Massachusetts, Trump’s edict could mean the erosion of state mandates such as one that says electricity must increasingly come from clean sources — such as offshore wind — and that all passenger vehicles sold in the state are electric by 2035.

It’s a step that upends a core underpinning of the Republican party as the defender of federalism and a state’s right to govern as it sees fit. But it aligns with efforts of conservative think tanks and some Republican states, which have long sought to staunch efforts to move from fossil fuels to clean energy.

“Trump is picking and choosing which states to strip of their sovereignty,” Sen. Ed Markey said in an emailed statement, vowing to continue work to “ensure that Trump’s Big Oil cabinet will not stop us from securing a healthy, livable future.”

It’s all part of a larger picture. Hours earlier, Trump signed an executive order aimed at reviving the coal industry, which has seen major declines in recent years as cleaner and less expensive forms of energy have taken over.

In New England, the order on coal is unlikely to make much of a difference, experts said, because the two remaining coal plants — both in New Hampshire — are required to close in the coming years based on a legal settlement. It’s unlikely that any new coal plants would be built in the region because they are more expensive to build and operate than other kinds of power plants (to say nothing of the cost to the climate).

Daren Bakst, director of the Center on Energy and Environment at the libertarian public policy organization Competitive Enterprise Institute, defended the new executive order, calling it “an important effort to examine what states are doing that undermine our ability to produce reliable and affordable energy.”

Bakst said that the order “rightfully” references policies that states employ to discriminate against out-of-state energy producers that impose major barriers to interstate trade.

That argument — that state laws to regulate emissions negatively effect out-of-state energy producers, in violation of federal law — hasn’t held up at the Supreme Court, said Ari Peskoe, director of the Electricity Law Initiative at the Harvard Law School Environmental and Energy Law Program. In 2023, the Supreme Court shot down that inter-state argument, he said, so it “doesn’t have a lot of sway now in courts.”

Massachusetts has passed several laws that aim to slash planet-warming greenhouse gases, making it a longtime leader in state-adopted climate legislation, while also bringing lawsuits to hold polluters to account. It’s also a long-standing member of the Regional Greenhouse Gas Initiative, a 16-year-old market-based program that sets a declining cap on emissions from power plants and charges them for the carbon they emit.

In 2019, then-Attorney General Maura Healey sued Exxon Mobil Corporation — the world’s largest publicly traded oil and gas company — for deceptive advertising to Massachusetts consumers and for misleading Massachusetts investors about the risks to Exxon’s business posed by fossil fuel-driven climate change. That case is ongoing, and now being argued by Attorney General Andrea Campbell.

In 2021, Gov. Charlie Baker signed a law requiring the state to slash emissions to half of 1990 levels by the end of this decade, and to essentially zero them out by mid-century. Subsequent laws signed by Baker and Healey have mandated increases in clean energy while offering pathways for some communities to start banning fossil fuels in new buildings.

Those laws put Massachusetts on a path. In order to achieve those emissions goals, the state needs to rapidly convert buildings off of fossil fuels, primarily by switching from oil or gas for heat to electric heat pumps; requiringelectric vehicles to replace gas ones; and deeming that electricitymust come from clean sources, like wind, solar, and hydro-electricity. Already, that work is underway, largely by offering a suite of incentives to residents, through Mass Save and other programs, while pursuing the development of clean energy resources, like wind and solar.

The latest executive order could put all of that at risk — that is, if Bondi is able to find legal grounds to fight the states.

“Just as the president’s tariffs have led to an economic disaster, this latest executive order is yet another unlawful overreach that will undermine the clean energy transition that is creating jobs, advancing new technologies, and protecting communities in Massachusetts and across the United States,” said Maria Hardiman, spokesperson for the state’s Executive Office of Energy and Environmental Affairs.

In response to the executive order, Hardiman noted that in recent years, the state has experienced historic floods, heat waves, drought, and wildfires, and that the effects of climate change are expected to get a lot worse. That dire picture includes an estimated additional 400 premature deaths each year due to extreme heat by the end of the century, and, if action isn’t taken, a ten-fold increase in coastal flood damage to commercial and industrial areas by 2090, according to the state.

The Trump administration argues that states’ efforts to slash emissions amount to an abuse of power. “The president is right to ensure that Americans in both red and blue states are not beholden to State overreach stifling American energy that are unconstitutional or contradict federal law,” said White House spokesperson Taylor Rogers.

Arguing a state energy policy is unconstitutional is “certainly a provocative step,” said Peskoe, of Harvard Law School, but this isn’t the first time Trump has tried this — and it hasn’t worked in the past.

During his first term, Trump took aim at California’s cap-and-trade program, which incentives companies to reduce their emissions while penalizing those that fail to meet required limits. The program was named in the recent executive order as a potential target for Bondi’s investigation. But the earlier effort to overturn that program failed.

“It’s not clear why they think they have a better chance this time around,” Peskoe said.

The executive order also calls out laws passed in Vermont and in New York state that aim to recover the costs of climate impacts, like flooding, from fossil fuel companies. But those laws were only recently passed.

“Typically, the Justice Department takes the position that until a law is actually implemented or enforced — and that’s years away, in Vermont and New York — there is no basis to be in federal court,” said Bradley Campbell, president of the Conservation Law Foundation.

Larry Chretien, executive director of the Green Energy Consumers Alliance, which works in Rhode Island and Massachusetts, said there’s nothing unconstitutional about the laws that govern climate action in either state — which means it’s unlikely that Bondi will find anything to challenge in state court.

“I see the executive order as another attempt to throw red meat to the fossil fuel industries,” he said. “No state should blink.”

Sabrina Shankman can be reached at sabrina.shankman@globe.com.