The Senate on Wednesday voted to overturn President Biden's stricter emissions rules for commercial trucks, halting their implementation unless the President vetoes the measure.

The 50-49 vote rescinds emissions rules that went into effect last month, marking the first time in 20 years that the EPA has set stricter standards for emissions from heavy-duty trucks. The agency has said the new rules are projected to cut nitrogen-oxide emissions from heavy-duty vehicles 48% by 2045, while costing an estimated $2,500 to $8,300 per vehicle.

Trucking companies and congressional critics of the new rules argued that the added cost as too much of a burden amid current driver shortages and supply-chain issues, according to Transport Topics.

Toyota Project Portal 2.0 fuel cell-powered semi-trailer truck

Toyota Project Portal 2.0 fuel cell-powered semi-trailer truck

The vote fell along party lines in the evenly-divided Senate, with all Republicans voting in favor of rescinding the stricter emissions rules. It's a bit of a turnaround in the composition of the Senate since a group of senators put the pressure on Biden in 2021 to start phasing out gasoline vehicle sales. West Virginia Senator Joe Manchin voted with Republicans to block the big-truck cleanup, while California Democratic Senator Dianne Feinstein, a longtime advocate of clean vehicles and part of that group, didn't vote and that essentially allowed the measure to pass.

It's not over yet, though. Biden has reportedly threatened to veto the legislation, which would require a two-thirds majority to overcome. That's unlikely to happen given the current Senate makeup.

The rules were to be a fit with California's mandate of electric trucks, starting in 2024, and the state's omnibus rules that impose limits on the truck fleet otherwise. They would also effectively be an extension of the plan that 17 states have stood behind, aiming to electrify 30% of trucks and buses by 2030.

Freightliner eCascadia

Freightliner eCascadia

President Biden set out to produce policy that resulted in union-made, U.S.-built electric cars. With the Inflation Recovery Act (IRA) and the infrastructure bill he got the latter plus an unprecedented investment in infrastructure.

Biden has also targeted that all light federal fleet purchases be electric by 2027, with an aspiration to make all federal vehicle acquisitions electric by 2035.