GOP leaders insist they aren't trying to end the 60-vote rule. Democrats warn that by ignoring the parliamentarian in this case, they are effectively "going nuclear" on the filibuster.

The Republican-led Senate moved Wednesday to overturn key Biden-era waivers allowing California to set its own vehicle emissions, a major blow to that state’s effort to regulate pollution from cars and trucks that could have broad environmental impacts for the rest of the country.

S.D., said that the Senate will begin to consider three House-passed resolutions that would roll back the standards. Final votes could come as soon as this week.