The tactics used by Democrats to secure at least 58 Senate seats may have damaged their chances of winning vital support from Sen. Susan Collins (R-Maine) in key votes in the 111th Congress.

Collins told colleagues at a small Senate prayer breakfast meeting last week that she still felt lingering resentment toward Democratic senators who campaigned against her in Maine.

Collins’s lingering resentment could emerge as a snag for Democratic leaders who expect her to side with them on many important votes.

Unless Democrats win a recount in Minnesota and a runoff in Georgia, Senate Majority Leader Harry Reid (D-Nev.) will need at least two Republicans to side with his conference on procedural votes next year to overcome GOP filibusters.

Collins’s spokesman, Kevin Kelley, said his boss does not hold a grudge.

“She has made clear that once the campaigns are over, politics needs to be set aside and Congress needs to get the job done,” Kelley said. “That’s something Sen. Collins has always done and something she’ll continue to.”

But other senators say that attacks on the campaign trail can have lasting repercussions in the clubby Senate, where one lawmaker’s objection can bring legislative progress to a halt.

“The Senate is a relationship business and [it]’s worth taking that into consideration,” said Sen. Norm Coleman (Minn.), another GOP centrist who breaks from his party occasionally. Coleman was also a target of Democrats this year and is awaiting the results of a recount to know if he won his bruising reelection race.

Collins and her home-state colleague, Sen. Olympia Snowe (R), have voted with GOP Senate leaders less often than any other Republicans. They are the two Republicans whom Democrats are expected to court most often.

Before Congress adjourned, Collins voted with Democrats and against her own leaders to advance an emergency stimulus bill. She also recently voted with Democrats to quash a Republican filibuster of the defense authorization bill.

Yet her willingness to cross the aisle from time to time didn’t stop Democrats from lobbing attacks during her recent campaign for reelection. Collins received her hardest shots from Democratic Sens. Frank Lautenberg (N.J.) and Sherrod Brown (Ohio).

During a campaign event in Portland, Maine, earlier this year, Lautenberg accused Collins of turning a blind eye to war profiteering in Iraq while she served as chairwoman of the Homeland Security and Governmental Affairs Committee.

“I was eager to get to the bottom [of dealings with] Halliburton, but the chair of the committee refused to look into it,” Lautenberg told reporters in February, according to PolitickerME.com.

Lautenberg also said that Collins blocked an effort to subpoena Vice President Dick Cheney about salary and stock options he had received from Halliburton.

Brown blasted Collins for voting regularly with President Bush and then falsely portraying herself as a party maverick to voters at home.