Little Rock, Arkansas (CNN) - Sen. Blanche Lincoln is campaigning across Arkansas Monday, one day ahead of a potentially pivotal Democratic primary.
But as the Democrat looks for votes, she faces grumblings from one key constituency that has overwhelmingly supported her in the past: African-Americans.
Lincoln is locked in a tight race with Arkansas Lieutenant Gov. Bill Halter. A third candidate, Arkansas businessman DC Morrison, has very little name recognition in the state and is registering low in the polls.
But support for Morrison could pull away votes from Lincoln and force a run-off between the top two vote getters. A candidate would have to receive at least 50-percent of the vote in Tuesday's primary to avoid a run-off.
Among the groups Lincoln is courting are African-Americans, a group that gave her 96-percent of its vote in the 2004 election. President Obama has endorsed Lincoln, and an ad featuring him is playing on black radio stations.
On Sunday, the senator attended a campaign event at a prominent, black-owned restaurant in Little Rock. The campaign billed it as "Hats Off to Senator Blanche Lincoln," – a play on words as the gathering of mostly African-American women, and the senator herself, wore fancy, colorful hats often seen in black churches.
"Other people are going to tell you about what they are going to promise. I can tell you what I've done," Lincoln told the small crowd. "And I've worked hard and I've produced."
Supporter Janet Davis Tate called Lincoln a "proven leader" and added, "She will be able to do more for African-Americans than her opponent will if he's elected."
Tamara Perry, an outreach coordinator for the Lincoln campaign, said, "Our intent for this was for African-American women. Reaching out to mothers, sisters, wives, people, any voter…some that were kind of on the fence."
When asked why some blacks might now waver in their support for the senator, Perry said, "They just didn't understand the facts of [Lincoln's record]."
The president of the Little Rock NAACP sees it entirely differently.
Dale Charles explained that the organization does not endorse candidates or parties. But Charles did highlight what the civil rights organization sees as items in Lincoln's record that are troubling to the black community.
Charles claimed that on key issues, including support for African-American farmers and helping to get black federal judges confirmed, Lincoln has done little.
Charles specifically noted the senator's positions during the congressional debate before the health care bill was signed into law.
Lincoln opposed a public option in the Senate bill and voted for the measure that ultimately emerged, lacking a public option.
On Sunday, Lincoln told CNN Senior Congressional Correspondent Dana Bash, "I think I took the right steps that were consistent with Arkansans. They didn't want another government funded, government run program."
Charles singles out Lincoln's health care stances as huge disappointments to African-Americans.
"Sen. Lincoln single-handedly killed the public option," he said, noting its popularity with many blacks. "Her state needed it most, of any state, because of the fact that we have a high percentage of people live in the Delta. And the lack of insurance…and access to doctors," Charles added.
Regarding Lincoln's later vote against the reconciliation package, Charles said, "If the reconciliation bill had failed would we have a health care bill?"
Charles summed up his argument this way, "I don't know how many people have really studied those issues enough to understand that those are crucial issues to the black community."
"And when we needed her, she wasn't there," Charles added.
Regarding Lincoln's performance on issues of concern to African-Americans, Charles gave her a grade of F.