Democratic senators including Sherrod Brown of Ohio, Bob Casey of Pennsylvania, Debbie Stabenow of Michigan and Jon Tester of Montana haven’t supported past efforts to stall climate rules, but they could change their minds with an eye on their 2012 races.

The GOP won gubernatorial races in Michigan, Ohio and Pennsylvania and flipped a dozen Democratic House seats last week.

“If you were Casey and Brown, I think you’d be thinking this would be something you’d have to look at,” said Ohio Coal Association President Mike Carey. “We are going to make sure that Ohioans understand how devastating this type of regulation … would be to their pocketbooks.”

Tester, a first-term Democrat from a state that backed Republican presidential candidate John McCain in 2008, could also be an easy pickup.

In June, a Senate resolution that would have essentially blocked the EPA's global warming rules failed, 47-53. The measure's sponsor, Sen. Lisa Murkowski (R-Alaska), promised to try again if she wins her write-in reelection vote.

"We must first pre-empt the EPA from meddling in the work of Congress when it comes to setting climate policies," Murkowski said in a statement last week.

Although Senate Majority Leader Harry Reid (D-Nev.) earlier this year promised moderate Democrats a vote on a measure to block EPA's greenhouse gas rules for two years, EPA foes are unlikely to get a chance during the lame duck to take such a vote. Besides, they'll have broader support if they wait until January.

“If the question does get called, those who want to put the brakes on the EPA have a much better vote count,” said Eric Ueland, who was chief of staff to former Senate Majority Leader Bill Frist (R-Tenn.).

Of the 53 senators who endorsed previous efforts to block or delay climate regulations, the 22 who were up for reelection this year either retained their seats or will be replaced by lawmakers expected to similarly support such measures. 

At least three Senate seats flipped from climate rule defenders to newcomers who will likely be eager to block EPA regulations. Democrats Russ Feingold of Wisconsin and Arlen Specter of Pennsylvania will be replaced by Republicans Ron Johnson and Pat Toomey, respectively, both of whom have opposed measures to curb greenhouse gas emissions. Former Rep. Mark Kirk (R-Ill.) — who’s taking Democrat Roland Burris’s Illinois Senate seat — voted for the cap-and-trade bill that passed the House last year but quickly said he would vote against the bill in the Senate.