States Challenge Federal Rollback of California’s Vehicle Emissions Waivers

Key Takeaways from the Multistate Lawsuit on EPA Waiver Rollback

• Multistate Legal Action:
  Eleven states—including California, New York, and Colorado—filed suit against the federal government for revoking Clean Air Act waivers through Congressional Review Act (CRA) resolutions.
• Targeted Emissions Standards: The lawsuit defends California’s Advanced Clean Cars II, Advanced Clean Trucks, and Omnibus Low NOx regulations—rules that several states have adopted to reduce vehicle emissions.
• Unprecedented Use of CRA: Plaintiffs argue that EPA waiver decisions are not “rules” under the CRA and therefore cannot be overturned by Congressional disapproval resolutions.
• Federalism and State Authority at Stake: The states claim the move infringes on their sovereignty under the Tenth Amendment, undermining their ability to enact stricter air pollution rules.
• Ignored Legal Guidance: The EPA, GAO, and Senate Parliamentarian had all previously determined that Clean Air Act waivers were not subject to CRA. Congress proceeded anyway.
• Implications for Climate Policy: The outcome could set a national precedent on whether federal lawmakers can dismantle state-level climate and clean air regulations without going through the full legislative process.

In a federal lawsuit filed June 12, 2025, California and ten other states are challenging the legality of three Congressional resolutions signed by President Trump that disapprove key EPA waivers. The waivers, granted between 2023 and early 2025, allow California to implement its Advanced Clean Cars II, Advanced Clean Trucks, and Omnibus Low NOx regulations—rules that several states have since adopted.

At the heart of the complaint is the assertion that EPA waiver decisions are not “rules” under the CRA and thus cannot be overturned by Congressional vote. The plaintiffs argue that the federal government violated long-standing legal interpretations and overstepped its authority by nullifying state-level climate action.

“Congress is using the CRA in a way it was never designed for—to strip states of their authority to protect their residents from pollution,” said California Attorney General Rob Bonta.

The Congressional Review Act, originally enacted in 1996, allows Congress to overturn federal regulations with a simple majority vote. However, this is the first time the CRA has been used to target Clean Air Act waivers, a mechanism created to recognize California’s unique air pollution challenges and technological leadership in emissions control.

Legal experts and the Government Accountability Office (GAO) have repeatedly held that such waivers are adjudicatory orders, not rules of general applicability, and therefore fall outside CRA jurisdiction. The Senate Parliamentarian reached the same conclusion prior to the resolutions’ passage.

Despite these findings, Congress moved forward with the resolutions, a move that plaintiff states say violates the Constitution’s separation of powers and infringes on state sovereignty. If upheld, the move could set a precedent allowing federal lawmakers to dismantle state-adopted environmental standards with little debate.

The lawsuit seeks declaratory and injunctive relief to block the enforcement of the CRA resolutions and preserve the EPA’s original waivers.

This case could have nationwide implications for state-led climate policy, emissions regulation, and the limits of federal legislative authority.