Several Democrats have joined Sen. Lisa Murkowski (R-Alaska) in trying to stop the Environmental Protection Agency from regulating greenhouse gases.

A joint resolution (S.J. Res. 26) with 39 co-sponsors, including three Democrats, was introduced Thursday on the Senate floor. It reflects a political shift in the chamber just days after Democrats lost the supermajority .

Until recently, Murkowski didn't have enough votes for her push. Now it seems possible that enough Democrats could deflect from the party line and join her as they court voters for midterm elections.

"We cannot turn a blind eye to the EPA's efforts to propose back-door climate regulation with no input from Congress," Murkowski said after introducing the resolution.

She prefers that regulation be left up to Congress, a stance with which most Democrats and even President Obama agree.

But legislation may no longer be an option.

Democrats are wary of tackling another divisive issue after losing the Massachusetts election. They are prioritizing jobs and financial overhaul , issues popular with voters.

"It's going to be very hard to put on the table another big issue in the near term," Sen. Robert P. Casey (D-Penn.) said.

Three Democrats -- Sens. Blanche Lincoln (Ark.), Ben Nelson (Neb.), and Mary L. Landrieu (La.) -- have already joined Murkowski by co-sponsoring the resolution.

“Heavy-handed EPA regulation, as well as the current cap-and-trade bills in Congress, will cost jobs and put as at an even greater competitive disadvantage to China, India and others," Lincoln said in a statement.

Murkowski has been working for months to negate the ruling that lets the EPA control carbon pollution under clean air laws.

"The EPA's regulations will not only add a thick new layer of federal bureaucracy, they also serve to depress economic activity," she said.

Murkowski tried to introduce an amendment last fall to stop the EPA, but lacked the 60 votes to get it through.

This resolution requires just 51 votes, and Murkowski believes she has enough Democrats on her side to pass it.

If it gets through the Senate, President Obama would probably veto it.

But it will have succeeded in undermining support for his cap and trade bill. The president has been pressuring Congress to move forward with his plan to let companies buy and trade pollution credits.

Many lawmakers believe that the threat of EPA regulation was just a tactic for the President to prod Senators into action.

"That strategy has failed so far and it will continue to fail in the months ahead because members of Congress will not enact bad legislation in order to stave off bad regulation," Murkowski said.

But now it seems that the EPA may be the only feasible route to control carbon emissions in the near future. Environmentalists determined to have at least one option are opposing Murkowski's move.

"This is an attack on the Clean Air Act, which is the one law we already have to tackle global warming pollution," said David Doniger, director of climate policy at the National Resource Defense Council.

Many Democrats still oppose the resolution, including Sen. Barbara Boxer (D-Calif.). She warned that it will have broader implications that could hamper efforts to curb greenhouse gases.

Boxer said Murkowski aims "to repeal a finding that was made by the science and health experts that carbon pollution is an endangerment to the health of our children, to our communities, and to our families."

Ambreen Ali writes for Congress.org.