In a significant political reversal, Senate Republicans have voted to repeal California’s longstanding authority to set its own air pollution standards for vehicles. In a 51-44 vote, senators canceled a special waiver that has historically enabled California to enforce stricter emissions regulations than federal standards. This waiver mechanism, established roughly half a century ago, had previously been granted to California more than one hundred times.
The decision carries broader national implications as 16 other states plus the District of Columbia closely align their vehicle emissions policies with California’s rigorous standards. Most of these states have also already put plans in place to phase out fossil fuel-powered vehicles.
California’s proposed rules mandated increasing sales quotas for zero-emission vehicles (ZEVs) beginning in 2026, gradually building up to a full-scale requirement by 2035. Under the policy, automakers would have had to shift exclusively toward zero-emission passenger cars and trucks within a decade. Currently, vehicle manufacturers offer two main zero-emissions technologies—battery-electric vehicles and hydrogen fuel-cell vehicles. However, due to ongoing challenges for hydrogen fuel-cell infrastructure, electric battery-powered vehicles have emerged as the dominant approach for meeting the state’s intended 2035 deadline.
California’s sales figures illustrate the increasing adoption of electric vehicles. Last year, zero-emission vehicles made up 25.3% of new passenger vehicle sales in the state, virtually all of them electric cars. California’s mandate aimed to increase that percentage to 35% by 2026, a target some automakers had described as unfeasible. After rapid growth between 2020 and 2023, ZEV market share in California plateaued in 2024.
In overturning the waiver, the Senate disregarded the advice of both the Government Accountability Office and the Senate parliamentarian. Both had previously concluded that such revocations were not permissible under the Congressional Review Act (CRA), legislation that allows Congress to overturn executive regulations via a simple majority without risk of filibuster. Additionally, senators expanded their repeal actions by striking down California’s separate waivers for higher emission standards for medium- and heavy-duty vehicles.
Prior to the vote, California Attorney General Rob Bonta indicated the state was ready to challenge any attempt to use the CRA to revoke its environmental protections, arguing such action misused the intent of the Congressional Review Act.
