Even as she fought for her own political survival in Arkansas on Tuesday, Sen. Blanche Lincoln (D-Ark.) vowed to “fight efforts to weaken” a key proposal she authored in the financial regulatory reform bill that could be significantly altered as the measure moves closer toward final passage.

Lincoln was not even in the Capitol on Tuesday because she was home facing a stiff Democratic primary challenge from Lt. Gov. Bill Halter.

“I remain fully committed to my provision and will fight efforts to weaken it,” Lincoln said in a statement. “I’m proud of the support my provision has received both inside and outside the Senate and will defend it should there be a debate on the Senate floor.”

Lincoln, who chairs the Senate Agriculture Committee, authored language folded into the reform bill that would significantly alter regulations of the derivatives market. Banking Chairman Chris Dodd (D-Conn.) filed an amendment to the financial reform bill Tuesday that would postpone action on Lincoln’s language for two years while the Treasury Department studies its impact on the markets. As one Democratic aide put it, Dodd’s move “essentially kicks the can down the road.”

The Senate is poised to vote on a procedural motion to end debate on the financial reform bill Wednesday. Lincoln’s measure, which did win the support of Republican Sen. Chuck Grassley (Iowa) in committee, has remained one of the more controversial sections of the financial reform package, and Dodd’s move Tuesday is an attempt to wrap up one of the remaining issues in the sweeping overhaul.