President Trump is expected Wednesday to revoke a decades-old rule that empowers California to set tougher car emissions standards than those required by the federal government — putting the state and the administration on a path to years of fighting in court.

The move, which has been in the works for much of the last three years, would overturn the foundation for California’s role as an environmental leader in reducing greenhouse gas emissions and improving air quality. By revoking a special waiver the state has relied on for years to set its own standards, the administration will be saying that no state can impose more ambitious pollution controls than those adopted by the federal government.

The Environmental Protection Agency, which will formally make the announcement, had no official comment on the plan, which is expected to be announced while Trump is in California for a campaign fundraising trip.

The administration’s plan to revoke the waiver is likely to set off years of legal battles that could eventually land at the U.S. Supreme Court. The move affects not only California, but also 13 other states and the District of Columbia that follow its emissions regulations.


Gov. Gavin Newsom called the administration’s plan part of a “political vendetta” against the state, and California Atty. Gen. Xavier Becerra said the administration had “no basis and no authority” for its action.

“It’s a move that could have devastating consequences for our kids’ health and the air we breathe if California were to roll over,” Newsom said in a statement. “But we will not — we will fight this latest attempt and defend our clean car standards.”

Democratic members of Congress said they would try to block the administration’s move. Rep. Doris Matsui (D-Sacramento), a member of the House committee that oversees the EPA, said she planned to seek legislation to keep the state’s authority intact. Although Trump likely would veto a free-standing bill to accomplish that, Democrats might be able to attach a provision to a budget measure or some other must-pass measure.

Hanging in the balance is whether California will continue to serve as a laboratory for tough new auto pollution rules and whether its regulations requiring automakers to sell more zero-emission vehicles and plug-in hybrids will survive. The state’s goal is to have more than 1 million of these vehicles on the road by 2025.


California’s special authority to go further than the federal government in regulating auto pollution dates back to the 1960s, when Los Angeles was enveloped in a thick layer of smog that state officials came to see as a public health crisis. By the time the 1970 federal Clean Air Act took effect, the state had already enacted its own tailpipe emission controls.

Concerned that each state would pass different regulations, Congress decided that the EPA would set vehicle pollution standards for the nation. But it carved out an exception for California, saying that the EPA would be required to grant the state a waiver to set its own rules, provided they were at least as stringent as the federal ones. Other states could choose to follow either California’s regulations or those set by the EPA.

The rule change to try to end that authority comes a few months after California spurned the White House by secretly negotiating a deal with four major automakers. As part of the pact, the car manufacturers — Ford, Honda, Volkswagen and BMW — agreed to voluntarily abide by California’s rules and increase fuel efficiency and reduce emissions, essentially ignoring the Trump administration’s plans to roll back tailpipe pollution standards.


“Crazy!” the president tweeted in response. “The Founders of Ford Motor Company and General Motors, are ‘rolling over’ at the weakness of current car company executives,” he wrote.

Other automakers, such as General Motors, have reportedly been interested in joining the agreement. The administration’s move to strip California of its authority to set its own emissions standards has been viewed by some of the president’s critics as retaliatory.

“It’s clearly a big slap at California,” said Ann Carlson, a professor of environmental law at UCLA. “It does make you wonder whether there’s a motivation here that’s political rather than legal.”

Dan Becker, director of the Washington-based Safe Climate Campaign, said, “Trump has married his administration-wide hostility to the environment to his personal vendetta against California.”


California has embraced its role as chief antagonist to Trump on environmental policies, suing the administration repeatedly over its agenda of dismantling Obama-era environmental and public health regulations. Federal judges have sided with California and environmental groups in cases concerning air pollution, pesticides and the royalties that the government receives from companies that extract oil, gas and coal from public land.

Further escalating tensions between the state and the Trump administration, the Department of Justice has launched an antitrust investigation into whether the automakers that reached the voluntary emissions agreement with the state violated federal competition law.

The EPA and the Department of Transportation also sent a letter to California regulators earlier this month warning of “legal consequences” if the state did not abandon its agreement with automakers. The letter reiterated the administration’s long-held belief that only federal agencies have the authority to set fuel economy and greenhouse gas emissions standards for cars.


The planned revocation of the state’s waiver is only one step in the administration’s plans to weaken car pollution standards.

Current rules put in place during the Obama administration require automakers to build increasingly efficient vehicles so that by 2025 the nation’s cars and trucks would average more than 50 miles per gallon.

Under Trump, the EPA and the National Highway Traffic Safety Administration have proposed weakening the standards by freezing mileage targets at about 37 miles per gallon for cars after 2020. While acknowledging their plan would increase oil consumption and greenhouse gas emissions, the federal agencies have argued that the current standards endanger drivers by making new, safer cars too expensive.

The administration’s announcement of that rollback has been repeatedly delayed, and it remains unclear whether officials will be able to complete the plan. Independent scientists have poked holes in the agencies’ data, senior political officials tasked with working on the rollback have left the administration and automakers have revolted in opposition to the president’s plans, which they say will hurt their bottom line.


Carlson said that revoking California’s waiver would not necessarily harm state regulators’ deal with automakers because the agreement is voluntary.

In fact, the move could backfire on the administration, she said.

If California’s waiver is revoked and the current Obama-era standards remain in place, automakers could actually be forced to lower emissions levels more than they had agreed to as part of their pact with California.


Times staff writers Phil Willon in Sacramento and Sarah D. Wire in Washington contributed to this report.