The sniping between Republican Sen. Norm Coleman and DFLer Al Franken is paying off big time for one of the U.S. Senate candidates -- latecomer Dean Barkley.

A new Star Tribune Minnesota Poll finds that support for the two leading candidates has eroded significantly since May, but that Coleman has sustained more damage. His lead over Franken has narrowed from seven percentage points in the spring to four now -- 41 percent to 37 percent -- just as one of the nation's most combative and expensive Senate races enters its final phase.

The beneficiary of the crossfire is Barkley, the Independence Party nominee who registers a robust support level of 13 percent among the 1,106 likely voters polled. He's been campaigning for only two months, mostly on his own shoe leather and the dim memory among voters that he served briefly in the U.S. Senate.

According to the poll, conducted Wednesday through Friday, and follow-up interviews with respondents, Barkley's success is less a credit to him than a measure of the growing disdain among voters for Coleman and Franken, whose war of words has steadily escalated.

Since the May poll, Franken's level of support has dropped seven percentage points, while Coleman's has fallen by 10 points.

"I don't know much about Dean Barkley, but I don't like the other two candidates," said Barkley supporter LaRaine Nielson, 61, a group home aide in Faribault.

Unfavorable impressions

The poll shows that Franken's efforts to paint Coleman as a White House yes man have worked. Since the spring, there's been a sharp rise in voters, now 62 percent, who see Coleman as someone who typically follows President Bush's lead. Only a quarter of the voters surveyed believe Coleman in an independent thinker.

But Franken's troubles also are evident in the poll. More voters continue to view Franken unfavorably than favorably, a trend he's been unable to shake as Coleman hammers at his temperament and lack of experience.

"Al Franken? He's a rascal," said Harriet Gjermundson, 85, of Minneapolis, a retired secretary who leans Republican. "Coleman may not be the greatest, but he's our only choice. [Franken] uses very bad grammar and he speaks dirty."

Cullen Sheehan, Coleman's campaign manager, said that the poll reflects his belief that the race will be close. "Clearly there's a drop in the numbers, probably for two reasons -- there's a third-party candidate in the race post-primary, and two, we've been relentlessly attacked by Al Franken and outside groups using millions of dollars," he said.

"There's no question this is going to be an exciting race," said Colleen Murray, a spokeswoman for the Franken campaign.

Barkley -- who was instrumental in Jesse Ventura's successful race for governor in 1998 and was appointed to the Senate by Ventura in 2002 to fill out the last two months of the late Paul Wellstone's term -- said the poll results confirmed that voters are tired of negative campaigning.

A SurveyUSA poll taken last week also showed the race close. That poll had Coleman at 41 percent, Franken at 40 percent and Barkley at 14 percent.

Both polls were conducted after Barkley won the Independence Party primary election on Tuesday, and both put him ahead of the 10 percent that Ventura registered at this point in the 1998 gubernatorial race.

"What propelled Ventura into contention was the debates, and that's my strategy too," Barkley said. "I plan on being completely candid with people and answer questions just as Ventura did, and when people see the stark contrast [with the other candidates] I think those numbers will change."

Officials with the three campaigns plan to meet today to iron out a schedule for debates this fall, Barkley said.

A struggle for parties' bases

The new Minnesota Poll, which has a margin of sampling error of 3.9 percentage points, plus or minus, shows that Coleman is winning the battle of the independents, even with Barkley in the race. The senator has support from 36 percent of them, compared with 30 percent for Franken and 24 percent for Barkley.

But Coleman and Franken are struggling to secure their party's base, as each lags behind his respective presidential ticket in support among his own party members. That problem is especially pronounced for Franken, who fares worse among Democrats than Coleman does among Republicans.

Coleman is more popular than Franken among men, 46 to 36 percent, while women are pretty evenly split between the two. Franken has more support among college graduates, and he does better than Coleman among likely voters in the seven-county metro area, 44 to 36 percent, while Coleman prevails in the rest of the state, 48 to 29.

Coleman does better than Franken with the extremes at either end of the income scale, and the senator gets some of his strongest support from white evangelicals.

After months of sharp-edged attacks by Franken depicting Coleman as a senator in lockstep with Bush and in thrall to Big Oil, the senator's vulnerabilities are more pronounced than ever. Just 42 percent approve of the way Coleman has handled his job -- a record low for him in the Minnesota Poll -- while 44 percent disapprove.

"I can't say that he's been a terrible senator, but at the same time in the last six years [he's] been following in step [with Bush]," said poll respondent Scott Thompson, 60, a retired Army master sergeant from Sartell who is for Franken.

Thompson said that Franken's failure to pay workers' compensation insurance and income taxes in the states he worked doesn't make much difference to him, a view shared by 62 percent.

Luke Nyberg, a subcontractor from Gilbert, said he's backing Coleman mostly because he doesn't like Franken.

"Coleman's relatively new, he hasn't been in there very long, so I understand he's going to toe the party line on a lot of things," said Nyberg, 29. "But [my vote is] more against Al Franken. I'd listen to him on his radio program, and he's just too far left for me, too socialist in his bent."

The broad dissatisfaction with the candidates of the two biggest parties is the key to Barkley's support, despite the fact that the poll found nearly one-third of voters have never even heard his name.

Carol Costello, a 75-year-old retired nurse living in Stillwater, said she supports Barkley because she doesn't "really feel comfortable with Franken or Coleman. ... Franken's past kind of bothers me, and Coleman is too close to Bush."

Kevin Duchschere • 612-673-4455