"I think we should make sure they are exempt since they are not the big greenhouse-gas producers," said Baucus.

But Sen. Barbara BoxerBarbara Levy BoxerThe ‘bang for the buck’ theory fueling Trump’s infrastructure plan Kamala Harris endorses Gavin Newsom for California governor Dems face hard choice for State of the Union response MORE (D-Calif.), chairwoman of the Senate Committee on Environment and Public Works, said the amendment would lead to greater pollution and undermine the EPA. 

The vote was the first of three votes being held Wednesday afternoon that would limit the EPA's jurisdiction over greenhouse-gas emissions. Four other votes unrelated votes will follow.