The lawsuit is the latest salvo in the escalating legal and political fight between President Trump and California, which has created uncertainty and divisions in the auto industry. Both domestic and foreign automakers are grappling with which standards to follow as they prepare to manufacture vehicles for U.S. consumers over the next decade.
On Thursday, the Environmental Protection Agency and the Transportation Department formally revoked the waiver allowing California to set stricter limits on tailpipe emissions than the federal government, as part of a broader effort to scale back federal rules requiring U.S. auto fleets to average nearly 51 miles per gallon by model year 2025. Trump officials have drafted a plan to freeze federal mileage standards at roughly 37 miles per gallon though model year 2026.
Xavier Becerra, the state’s attorney general, argues in the lawsuit filed in the U.S. District Court for the District of Columbia that the administration overstepped authority given by Congress in withdrawing a waiver California has used to cut greenhouse gas emissions linked to climate change.
“The Oval Office is really not a place for on-the-job training,” Becerra said in a statement. “President Trump should have at least read the instruction manual he inherited when he assumed the presidency, in particular the chapter on respecting the rule of law. Mr. President, we’ll see you in court.”
The cities of Los Angeles and New York, along with the District of Columbia, also joined in Friday’s lawsuit. The mayors of Los Angeles, New York and D.C. are Democrats. And all but two of the states in the lawsuit, Massachusetts and Maryland, have Democratic governors, though the attorneys general in those two states are Democrats.
A total of 13 states and the District have pledged to adopt California’s tailpipe emissions standards if they are stricter than those of the federal government. Collectively, the group represents roughly 30 percent of the nation’s auto market.
In July, four automakers — Ford, Honda, Volkswagen and BMW of North America — struck a deal with California to produce cars and light trucks through model year 2026 that would reach a fleetwide mileage average of nearly 50 miles per gallon by 2026. The Justice Department is investigating whether the agreement violated federal antitrust law.
California had enjoyed a long-standing exemption under the Clean Air Act to ask for federal waivers to impose stricter air pollution standards, and received its most recent waiver as part of a broad agreement among the Obama administration, the auto industry and the state to set the first national carbon limits on vehicles.
In taking back the waiver, Trump officials argued that only the federal government has the right to set fuel economy standards under the 1975 Energy Policy and Conservation Act and that California did not have the right to use its exemption under the Clean Air Act to regulate carbon pollution linked to climate change because that ranks as a global problem.
In a statement, EPA spokeswoman Corry Schiermeyer said that the waivers are only given so that California can tackle “local pollution.”
“EPA has granted those waivers over many years. But California cannot misuse that authority to set national fuel economy standards and attempt to control national greenhouse gas emissions standards,” she said. “We are confident we are correctly applying the law and will prevail in the courts.”
But Becerra, who has sued the Trump administration 60 times since the president took office, pointed to two 2007 federal court decisions as precedent that would bolster the state’s case in court. In both cases, Green Mountain Chrysler Plymouth Dodge Jeep v. Crombie and Central Valley Chrysler-Jeep Inc. v. Goldstene, judges ruled that state limits on carbon dioxide emissions from cars and light trucks did not violate existing federal law.
“Two courts have already upheld California’s emissions standards, rejecting the argument the Trump Administration resurrects to justify” the withdrawal, Becerra said.
Trump and his deputies argue that less stringent mileage requirements will keep the sticker price of vehicles lower and spur drivers to replace older cars with newer, safer models.
Revoking California’s waiver, the president tweeted, will make “cars substantially SAFER.”
The EPA and the Transportation Department plan to finalize the revised rule by the end of the year.