Highlights
- Congress has passed three Congressional Review Act (CRA) resolutions to nullify a set of California's Clean Air Act (CAA) preemption waivers. President Donald Trump is expected to sign them.
- Environmentally, these actions mark the most significant threat ever to California's unique ability to set vehicle emission standards – an authority with roots that trace back to the Air Quality Act of 1967, before the modern Clean Air Act was enacted.
- Procedurally, these actions establish a new congressional precedent, with Congress invoking the CRA against agency actions that the Government Accountability Office (GAO) had explicitly determined were not "rules" subject to the CRA.
- This Holland & Knight alert reviews the nullification actions and how they could affect California, other states and regulated entities.
In the weeks since Holland & Knight previously reported on challenges to California's Clean Air Act (CAA) preemption waivers on April 30, 2025, Congress has taken decisive action. Following the U.S. House of Representatives' passage of three Congressional Review Act (CRA) resolutions in late April and early May, the Senate passed all three resolutions on May 22, 2025. President Donald Trump is expected to sign them.
These congressional actions represent the most significant challenge ever to the exercise of California's unique authority under CAA section 209(b), a provision that traces its roots over a half-century back to the Air Quality Act of 1967. Passage of the resolutions calls into question the fate of several major programs, including California's Advanced Clean Trucks, the "Omnibus" Low NOx regulation and Advanced Clean Cars II, some of which have been adopted by more than a dozen other states.
Beyond the CAA, Congress' action also raises the specter of CRA actions on a wide swath of other agency actions that had previously been thought to be off-limits. The U.S. Government Accountability Office (GAO) had previously determined that the CAA waivers are not "rules" under the CRA and are, therefore, beyond its scope. By proceeding with CRA resolutions anyway, the door has been opened to potential congressional review of other actions that GAO has deemed not to be rules – covering topics as diverse as drug approvals,1 broadcast licenses,2 hydroelectric dam licenses,3 oil leases4 and more.
Congressional Action
With the Senate's votes on May 22, 2025, Congress has now passed three CRA resolutions targeting different aspects of California's vehicle emissions program:
- H.J.Res. 87 disapproves the U.S. Environmental Protection Agency's (EPA) waiver for multiple California heavy-duty vehicle programs, including Advanced Clean Trucks (requiring increasing percentages of zero-emission truck sales), Zero Emission Airport Shuttles and Zero-Emission Power Train Certification.5
- H.J.Res. 88 disapproves the EPA's waiver for Advanced Clean Cars II, which required all new passenger cars, trucks and SUVs sold in California to be zero-emission by 2035.6
- H.J.Res. 89 disapproves the EPA's waiver for the "Omnibus" Low NOx regulation, which establishes more stringent emissions standards for heavy-duty vehicles.7
Unprecedented Congressional Procedural Battle
Passage of the resolutions came after a procedural battle with potentially far-reaching implications for congressional and agency operations. The House and Senate moved forward with CRA resolutions for the EPA-granted waivers despite both the GAO and Senate Parliamentarian having determined that California waivers are not "rules" subject to the CRA.
Before advancing the resolutions, the Senate voted 51-46 on a point of order regarding the types of joint resolutions "entitled to expedited procedures" under the CRA. The party-line vote, which Senate Democrats strongly opposed as a "procedural nuclear option," effectively set aside decisions of the GAO and Senate Parliamentarian. In a May 1, 2025, letter, Senate Minority Leader Chuck Schumer (D-N.Y.) and top Democrats warned that this approach could allow the CRA to be "weaponized to retroactively invalidate decades of agency actions" never previously considered to be rules, including "adjudications, permits, and licensing decisions." If Congress can itself decide what is subject to the CRA, many agency actions previously thought to be outside the CRA realm could now be invalidated – and agencies would arguably be prevented by the CRA from issuing future "rules" that are "substantially the same" as the disapproved ones.8
Republican Majority Leader John Thune (R-S.D.) defended the Senate's actions by arguing that GAO had inappropriately inserted itself into the process, that the Trump Administration EPA had submitted the waivers to Congress as "rules," and that the Senate has the right to determine its own procedures. Majority Leader Thune pushed back against arguments by Sen. Adam Schiff (D-Calif.) that the move was "setting a precedent that the filibuster is essentially now meaningless," – stating that "while Republicans are in charge, the legislative filibuster will remain in place, and you can take that to the bank."
Implications for Regulated Entities, California and Section 177 States
With the CRA resolutions headed to President Trump's desk for signature, California and the 17 states that have adopted its light-duty vehicle standards, along with the 10 states that have adopted its heavy-duty vehicle standards under CAA Section 177, face significant regulatory uncertainty.
Many have questioned whether the CRA may lawfully be used to review the EPA's waivers, and litigation is all but certain. Assuming Congress' actions survive judicial scrutiny, the effect will be to invalidate EPA's waiver decisions – thereby preempting California's authority to enforce these standards, and precluding other states from adopting the California standards as well. Additionally, absent new congressional authorization, EPA would be prohibited from issuing new "rules" in the future that are "substantially the same" as the disapproved waivers.
For vehicle and engine manufacturers, fleet operators and other stakeholders, these developments create both immediate compliance questions and longer-term planning challenges:
- With these regulations already in effect in California and many other states, companies may need to reassess their compliance obligations and recalibrate product development plans, including the degree to which they plan to accelerate deployment of zero-emission vehicles covered by these California rules.
- However, major original equipment manufacturers (OEMs) entered into agreements with California promising to comply with regulations, including those subject to the CRA resolutions, "regardless of the outcome of any litigation challenging the waivers/authorizations for those regulations, or [the state's] overall authority to implement those regulations." The Clean Truck Partnership and similar voluntary agreements between states and manufacturers may thus take on increased importance as nonregulatory mechanisms for emission reductions.
- California and other states may pursue alternative regulatory approaches that do not require CAA waivers, potentially creating a patchwork of requirements. Notably, regulation of indirect sources such as warehouses has become of increasing interest in both California and New York as a means for states to target mobile sources without the need for CAA waivers.
What's Next?
Once signed by President Trump, several developments are likely:
- Legal Challenges. California and environmental groups will likely challenge the application of the CRA to these waivers, including on the basis that they were not "rules" subject to CRA disapproval. As discussed in Holland & Knight's previous alert, the CRA has an unusual judicial "non-review" provision that could complicate these "efforts."
- Alternative State Actions. California may pursue alternative regulatory approaches, including Indirect Source Review (ISR) rules targeting facilities, such as ports and warehouses, and enhanced incentive programs to encourage the transition to zero-emission vehicles.
- Federal Agency Actions. The EPA may take additional steps to limit state authority over vehicle emissions, potentially revisiting other CAA waivers not covered by these CRA resolutions, including on "major question" doctrine grounds. The EPA and the National Highway Transportation Safety Administration may also seek to resurrect arguments from the first Trump Administration that California standards are preempted by the Energy Policy and Conservation Act.
- Congressional Activity. Congress may consider using the CRA for other agency actions previously thought to be outside the CRA's scope, including federal permits, leases, adjudications, drug approvals and licensing decisions. The consequences could be far-reaching, especially in the Senate, where these actions continue a trend of seeking routes to legislate that avoid the Senate legislative filibuster.
Footnotes
1 https://www.gao.gov/products/b-334995.
2 https://www.gao.gov/products/b-332233.
3 https://www.gao.gov/products/b-335030.
4 https://www.gao.gov/products/b-335781.
5 88 Fed. Reg. 20688 (April 6, 2023).
6 90 Fed. Reg. 642 (Jan. 6, 2025).
7 90 Fed. Reg. 643 (Jan. 6, 2025).
8 See 5 U.S.C. § 801(b)(2).
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