(CNN) - A new poll indicates that the GOP is on the cusp of capturing an Arkansas Senate seat last held by a Republican in the 1870s.
According to a CNN/Time/Opinion Research Corporation poll released Wednesday, 55 percent of likely voters now support four-term Republican Rep. John Boozman for November's general election. Only 41 percent back two-term incumbent Democratic Sen. Blanche Lincoln.
Two percent back neither candidate, while another two percent offered no opinion.
The race is only marginally tighter among the larger pool of registered voters, where Boozman holds a 53 to 42 percent lead.
Independents are breaking sharply for Boozman, favoring the Republican over Lincoln by a 63 to 29 percent margin.
One likely drag on Lincoln's re-election prospects: the strong disapproval of President Barack Obama in Arkansas. Only one in three Arkansas voters approves of Obama's job performance; more than six in ten disapprove.
Obama lost the increasingly Republican state to Arizona Sen. John McCain by 20 points in 2008.
Obama's unpopularity may be undercutting the efforts of another Arkansas political veteran - former President Bill Clinton - who has repeatedly tried to help Lincoln this year.
Clinton most recently teamed up with Lincoln at a campaign event in Jonesboro last Wednesday. He also backed Lincoln in a fiercely contested Democratic primary against Lt. Gov. Bill Halter, who enjoyed the support of a number of progressives and union leaders.
In addition to relying on Clinton, Lincoln has also played up her ability to help the Arkansas economy through her role as chairwoman of the Senate Agriculture Committee. So far, however, it seems her campaign pitch isn't sufficient to buck the apparent Republican tide.
"Lincoln has a three-point advantage among lower-income Arkansans," says CNN Polling Director Keating Holland. "But Boozman has a commanding 18-point lead among Arkansas voters who make more than $50,000 a year."
One bright spot for Arkansas Democrats: first-term incumbent Gov. Mike Beebe is leading GOP challenger Jim Keet by a whopping 27-point margin - 62 to 35 percent - among likely voters.
Beebe's margin is nearly identical among registered voters.
The CNN/Time/Opinion Research Corporation poll was conducted October 15-19, with 1,505 adults, including 1,260 registered voters and 809 likely voters questioned by telephone. The survey's overall sampling error is plus or minus 2.5 percentage points, with a sampling error of plus or minus 3.5 percentage points for likely voters.
- CNN's Alan Silverleib contributed to this report