The Senate voted Thursday to axe California’s phaseout of new gas-powered cars, making a controversial move to sidestep the parliamentarian in the process.

The vote was 51-44, and the measure now heads to President Trump’s desk; he is expected to sign it.

The move is a massive one for the U.S. vehicle market and for the planet, as automakers would no longer have to work toward an electric-only future in California and the 11 other states that have adopted its rule.

But it also has significance regarding Senate procedure, as the upper chamber moved to circumvent a ruling from its parliamentarian finding that it could not vote down the measure with just a simple majority. 

What the Senate actually overturned is not the California mandate itself, but the Biden administration’s approval of the Golden State’s policy.

The parliamentarian determined that the Environmental Protection Agency (EPA) approval was not subject to a congressional maneuver that allowed it to evade the filibuster’s 60-vote threshold. 

Both the House and Senate have voted to axe federal approval of California’s standard using the Congressional Review Act (CRA), which allows Congress to strike down recently approved regulations with a simple majority.

But the Senate parliamentarian and Congress’s Government Accountability Office (GAO) have found that the Biden administration EPA’s decision is not subject to the act because it is a waiver, not a regulation.

However, Senate Majority Leader John Thune (R-S.D.) held a series of procedural votes Wednesday night that aimed to sidestep the parliamentarian’s ruling.

In particular, he raised “points of order” that allowed the Senate to vote for itself on whether EPA waivers are subject to be overturned by the CRA.

“When the Senate is facing a novel situation like this one … it is appropriate for the Senate to speak as a body to the question, something the Senate does when questions over applications of the rules arise,” Thune said during a floor speech.

In response, Sen. Sheldon Whitehouse (D-R.I.) reiterated that the waiver is not a rule.

“What was unprecedented was for the House to send over a document, claiming, falsely according to the parliamentarian, that the waiver is in fact a rule under the CRA and to blame the GAO or the parliamentarian for that is to mistake the referee from the player that committed the foul.”

“The foul here is pretending that a waiver is a rule and both the GAO and the parliamentarian independently blew the whistle on that foul.”

Democrats this week have accused their Republican colleagues of “going nuclear” arguing that ignoring the parliamentarian’s decision undercuts the filibuster under which most Senate legislation requires 60 votes to pass. 

The Clean Air Act allows California to set stricter-than-federal standards for vehicular pollution, with EPA approval, due to its historic smog problems. In 2022, the state said it would ban new sales of gas-powered cars by 2035. 

The Biden administration approved that rule in December 2024.