LITTLE ROCK (AP) — Six years ago, Blanche Lincoln was the candidate who could please most of the people most of the time. The Democratic senator won re-election with the backing of both the Arkansas AFL-CIO and the U.S. Chamber of Commerce, groups that rarely agree on issues.

The opposite seems to be true now as Lincoln seeks a third term in the Senate. Lincoln faces her lowest job approval numbers, Republicans are lining up to run against her this fall and the state's lieutenant governor is actively flirting with a primary challenge.

As she prepares to file for re-election Monday, Lincoln has become emblematic of the problems faced by Democrats, and more broadly, incumbents, in the 2010 campaign. She is now considered by some political handicappers to be the Senate's most vulnerable member.

With the economy still sagging, polls show many voters have become impatient with the lack of jobs, the soaring federal deficit and with elected officials who seemed locked in partisan infighting.

Lincoln has worked hard to insulate herself from the souring mood. She's been virtually running against her own party's agenda on controversial issues such as the health care overhaul and ambitious spending proposals. But the tactic has drawn the ire of Democratic activists who are now publicly criticizing her. Meanwhile, her centrist approach doesn't seem to be winning over conservatives, with a growing field of Republican challengers in the race.

Lincoln finds herself the target of well-funded attack advertising from both sides of the political spectrum.

"There's a tremendous amount of noise out there that's very confusing to people," Lincoln said in an interview with the Associated Press. "They hear from the one side how terrible I am, and then they hear from the other side how terrible I am."

Her ability to withstand the crossfire is considered a sign of the Democratic Party's ability to maintain a foothold in Republican-leaning states like Arkansas in the election.

The University of Arkansas' annual Arkansas Poll in November reported that that just 43 percent of those polled approve of the job Lincoln is doing as senator, the lowest rating she has seen since she took office in 1999. She enjoyed a 54 percent approval rating last fall.

The poll numbers have prompted a Republican field of eight who hope to challenge Lincoln in the fall. Republicans say they believe she is beatable and are increasingly trying to tie her to President Barack Obama, who lost the state's six electoral votes in 2004 and who remains unpopular in Arkansas.

"He has put forth a very liberal agenda which she has been called on to support because of her party affiliation," Republican Party Chairman Doyle Webb said. "That agenda is not supported by the people of Arkansas, particularly the health care agenda."

Lincoln's vulnerability raises hopes for Republicans in a state where Democrats hold three of the four congressional seats, all the statewide offices and a solid majority in the state Legislature. That hope has been heightened by two of the state's Democratic congressmen — Vic Snyder and Marion Berry — scrapping their re-election bids.

Lincoln has taken steps in the past year to highlight her independence. In a recent meeting between Obama and Democratic senators, Lincoln challenged the president to work more with Republicans on key issues.

"Are we willing as Democrats to also push back on our own party and look for that common ground that we need to work with Republicans?" Lincoln asked.

Lincoln says she's not going out of her way to disagree with Obama.

"I think I can be very clear to Arkansans, and I think they will understand, that when President Obama presents a good idea and it's good for Arkansas I can be supportive," Lincoln said. "If it's something that's not good for Arkansas, not good for the people or the industries of Arkansas, it's going to be something I'm not going to support."

How much Lincoln will be able to distance herself remains to be seen. She launched her re-election with a fundraiser that featured Vice President Joe Biden last year, but says she doesn't expect Obama to stump for her in the state.

Liberal activists have accused Lincoln of moving to the right in a bid to save her seat.

Labor unions have sharply criticized her for her opposition to a key union-organizing bill, as well as her vote to block Obama's nominee to the National Labor Relations Board.

Alan Hughes, the Arkansas AFL-CIO's president, said Lincoln will have a tough time winning the union's endorsement again. "A lot of our members feel like, who is Blanche Lincoln? Is she a Democrat or a Republican?" Hughes said.

It's a question several groups on the left are asking. has criticized Lincoln for opposing a government-run insurance option as part of health care reform and has urged its members in Arkansas to ask Democratic Lt. Gov. Bill Halter to challenge Lincoln.

MoveOn and the Sierra club also launched television and radio ads targeting Lincoln for opposing proposed new steps to reduce the pollution blamed for global warming.

"We encouraged Halter to run because the people of Arkansas deserve a choice in the primary," said Justin Ruben,'s executive director. Halter, a former Clinton administration official, said he's considering all options.

Lincoln, who said she's not worried about whether Halter runs, said she believes she can live up to the Democratic Party's principles while trying to work with both parties.

"It's important to note that I'm not the only Democrat in those positions," Lincoln said. "There are other moderates, and there are moderate Republicans."

Lincoln's allies have said it's too early to write off her campaign, and note her campaign war chest of more than $5 million — more than all of her eight Republican challengers combined have raised.

Democrats also point out the bruising primary battle the Republicans face. Congressman John Boozman, the apparent front-runner, has been battered by rivals painting him as a Washington insider.

Lincoln also enjoys the elevated position as the chair of the Senate Committee on Agriculture, Nutrition and Forestry.

Democratic Party Chairman Todd Turner said he believes Lincoln's chief problem is the anti-incumbent sentiment, but that in the end, "I think people are going to recognize what she's done for the people of Arkansas."