Sen. Blanche Lincoln (D-Ark.), facing the prospect of a tough re-election bid next year, is under pressure from a liberal activist group to support a motion to proceed on health care reform legislation that is poised to hit the Senate floor next week.Lincoln has been on the fence on whether she would support a bill with a government-funded public insurance option. The Blue America political action committee is hitting statewide Arkansas cable television with a 30-second spot demanding that Lincoln allow an up-or-down vote on the public option.Blanche Lincoln claims to fight for health care reform. But whose interest does she really represent? the ads voiceover says as the spot opens. Lincoln has taken thousands from PACs from Blue Cross Blue Shield, Cigna, Aetna and United Health Group over $2 million from the health and insurance industries combined. Thats why 56 percent of voters think these contributions hurt her judgment on health care, the ad continues. With one in four Arkansans uninsured, lets save sponsorships for the race cars. Help Sen. Lincoln get back on track.The five-figure ad buy is scheduled to hit the airwaves this week and run for about two weeks. Senate Majority Leader Harry Reid (D-Nev.) is planning to drop the health care reform bill next week, but Lincoln has so far refused to commit to supporting a motion to proceed to begin debate, awaiting the final language of the bill.The legislation includes a public insurance option with an opt-out provision for states that do not want to participate. But the balance of the package remains under wraps pending the completion of the Congressional Budget Office analysis. Lincolns moderate Democratic colleagues have been similarly noncommittal on the motion to proceed.