A federal judge has interrupted the Trump administration’s latest attempt to dismantle California’s special authority over vehicle emissions, preserving several longstanding Clean Air Act waivers while a broader legal battle continues. On September 2, U.S. District Judge Beryl Howell ordered the Environmental Protection Agency to undo its June reclassification of four California waivers as federal “rules” that could be sent to Congress for fast-track repeal. The decision matters far beyond Sacramento because California standards have long influenced vehicle planning across the United States, while Canada and Mexico remain tied to the same manufacturing system through deeply integrated supply chains. Yet the ruling has limits: it does not automatically restore California’s separate 2035 zero-emission vehicle mandate, which Congress targeted in 2025 and which remains the subject of different litigation. The result is renewed regulatory uncertainty for automakers already navigating tariffs, EV investment shifts and the CUSMA review.
The Judge Blocked EPA’s New Route to Congress
Judge Beryl Howell’s order is a preliminary injunction, not a final judgment on every legal question surrounding California’s emissions authority. It blocks EPA from treating four previously issued Clean Air Act waivers as “rules” under the Congressional Review Act and directs the agency to restore the status quo that existed before its June 12, 2026 announcement. The waivers had been granted between 2009 and 2024 and cover vehicle emissions programs plus standards for small off-road engines.
That distinction matters because lawmakers were preparing to consider the waivers for repeal after EPA sent them to Congress. Howell concluded that EPA’s reclassification was likely unlawful and rejected the agency’s argument that its actions were effectively beyond judicial review. Her opinion focused on EPA’s inconsistent positions: the agency had historically treated California waiver decisions as adjudicatory orders, then recharacterized them as rules when doing so opened access to the CRA’s expedited repeal process.
Why the Congressional Review Act Changes the Stakes
The Congressional Review Act is powerful because it gives Congress a procedure for overturning federal agency rules. Under the CRA, a resolution of disapproval can move through the Senate without barriers that often force supporters of ordinary legislation to assemble 60 votes. If both chambers approve a resolution and the president signs it, the targeted rule loses legal force. EPA’s 2026 strategy depended on first placing California’s waivers inside that framework.
The stakes extend beyond one vote. A CRA disapproval can also bar an agency from issuing another rule in “substantially the same form” unless Congress later authorizes it. That is why Howell treated EPA’s classification move as more than paperwork. If a waiver could be converted into a CRA rule years after it was granted, congressional repeal could constrain future EPA administrations as well as California. The court viewed that consequence as a reason to scrutinize the reclassification itself.
California’s Special Authority Dates Back Nearly 60 Years
California occupies an unusual place in U.S. air-pollution law. Since 1967, Section 209 of the Clean Air Act has allowed the state to seek federal waivers permitting vehicle-emission standards stricter than national requirements. Congress made that exception because California had begun regulating vehicle pollution before the federal government and was confronting severe smog. The arrangement created controlled state experimentation rather than a system in which every state could invent a different vehicle standard.
Congress expanded California’s influence in 1977 by allowing other states to adopt California standards under Section 177, provided they follow the California program rather than design unique alternatives. Howell’s opinion noted that 17 states and the District of Columbia have adopted many California standards over time. It also emphasized how durable the waiver system has been: across half a century, EPA has denied California a waiver in full only once, underscoring how exceptional the current confrontation is.
Four Older Waivers Are at the Centre of This Case
The four waivers at the center of the September ruling are not identical. EPA’s June 2026 announcement identified a 2009 waiver for greenhouse-gas standards, the Advanced Clean Cars I waiver, the reinstatement of portions of Advanced Clean Cars I, and amendments covering small off-road engines. EPA argued that each had national consequences because California standards can still be adopted by other states and influence manufacturers designing products for the wider market.
For automakers, Advanced Clean Cars I matters because it combined tighter smog standards, greenhouse-gas controls and zero-emission vehicle requirements through the 2025 model-year framework. The 2009 greenhouse-gas waiver supported California standards beginning with 2009 model-year vehicles. Howell’s injunction protects those waiver orders from EPA’s new CRA pathway while the case proceeds. It does not erase federal authority or convert every California regulation into a permanent national standard; it preserves the pre-June legal position for the waivers before the court.
The Ruling Does Not Restore California’s 2035 EV Mandate
The biggest source of confusion is California’s Advanced Clean Cars II program, which is separate from the four waivers covered by Howell’s September injunction. ACC II was adopted in 2022 and was designed to ramp zero-emission vehicle requirements beginning with the 2026 model year, reaching 100% of new passenger-car and light-truck sales by 2035, including qualifying plug-in hybrids. EPA granted California the necessary federal waiver in December 2024.
Congress then used the Congressional Review Act in 2025 to disapprove that waiver along with waivers tied to Advanced Clean Trucks and a heavy-duty emissions program, and President Trump signed the resolutions. California and allied states sued, arguing that Congress had used the CRA unlawfully against waiver decisions. That separate case remains active. The September 2026 ruling strengthens California’s hand in a related legal theory, but it does not revive the 2035 mandate or require automakers to immediately resume ACC II compliance.
Automakers Have Been Pushing for One Predictable Rulebook
Automakers have pushed for regulatory certainty while investing in electrification. The Alliance for Automotive Innovation, which represents major manufacturers, supported congressional action against Advanced Clean Cars II in 2025 and argued that the California program would reach roughly 30% of the U.S. new-vehicle market once other adopting states were counted. Its concern was not simply California’s size, but the possibility that several large states could shape national product allocation through one state-designed sales requirement.
The industry’s position has been more nuanced than rejecting electric vehicles. When the Senate moved against ACC II, the Alliance said automakers had 144 electrified models on the U.S. market and described transportation as moving toward a mix of battery-electric, hybrid and plug-in hybrid products. Toyota, General Motors and other manufacturers lobbied for relief from California’s 2035 rules. The preference is for a predictable national framework that lets companies plan factories, inventories and compliance years ahead.
Canada Has Already Rewritten Its Own EV Strategy
Canada is watching this fight from a regulatory position than it occupied a few years ago. In February 2026, Prime Minister Mark Carney’s government announced that it would repeal the federal Electric Vehicle Availability Standard and replace it with stronger greenhouse-gas standards for light-duty vehicles. Ottawa said the approach would be technology-neutral early while becoming more stringent over time, with the policy expected to drive about 75% EV adoption by 2035 and an aspirational 90% by 2040 across Canada.
That shift makes U.S. policy uncertainty more relevant. Canada’s strategy still depends on a growing EV market, backed by a $2.3-billion affordability program and $1.5 billion in charging-infrastructure investment, but it no longer relies on a hard 100% ZEV sales requirement for 2035. If U.S. federal rules, California rules and Canadian standards keep diverging, manufacturers may face different compliance assumptions for vehicles built from the same North American platforms and components.
One Regulatory Change Can Ripple Across Three Countries
The reason a California courtroom can matter to Ontario, Michigan and northern Mexico is the structure of the auto industry. Canada says more than 90% of Canadian-made vehicles and 60% of Canadian-made auto parts are exported to the United States. In 2025, Canadian plants produced more than 1.2 million passenger vehicles, while the manufacturing sector supported 121,000 direct jobs and contributed about $17.1 billion to Canadian GDP. Many Canadian-built vehicles contain substantial U.S. content.
Mexico is embedded in the system. U.S. Commerce Department guidance says some parts cross the U.S.-Mexico border as many as a dozen times before a product emerges, and nearly 80% of Mexico’s light-vehicle exports went to the United States in 2024. This is why different emissions regimes are not isolated choices. A change in one major market can alter engineering decisions, model allocation, supplier orders and factory economics throughout a production network designed around continental scale.
The Regulatory Fight Is Colliding With the Tariff Fight
The emissions dispute is landing on top of an already difficult trade environment. Since April 2025, Canadian vehicles entering the United States have faced a 25% tariff on non-U.S. content, even when they qualify under CUSMA rules of origin. Canada responded with counter-tariffs and a remission system intended to reward automakers that maintain Canadian production. The sector is calculating tariffs, origin rules and investment commitments before another layer of environmental compliance is added.
Those pressures are converging with the 2026 CUSMA review. Canadian officials met North American auto-industry representatives in June to discuss tariffs, manufacturing competitiveness and preserving an integrated regional sector, while U.S.-Mexico talks have highlighted automotive rules of origin. Regulatory compatibility is therefore part of a larger competitiveness debate. An automaker deciding where to build a future hybrid, EV or gasoline model must consider consumer demand, tariff exposure and which emissions regime will govern its largest sales markets.
The Courtroom Battle Is Only Entering Its Next Phase
The immediate effect of Howell’s injunction is to shut down EPA’s 2026 reclassification route while the lawsuit continues. The agency must restore the earlier status of the four waivers and is barred, for now, from taking further steps to reclassify California Section 209(b) waiver orders as CRA rules. Because the ruling is preliminary, the administration can keep litigating the merits and may seek appellate review. Reuters reported that EPA did not immediately comment.
The conflict is far from settled. California is litigating the 2025 congressional disapproval of the Advanced Clean Cars II waiver, while industry groups, fuel interests and states remain active in cases. For North American manufacturers, the question is not whether California wins one lawsuit. It is whether the United States returns to one national framework, preserves a California track, or keeps oscillating between the two. Each outcome creates different investment signals for Canada, Mexico and U.S. factories.
