WASHINGTON – More than half of Minnesotans say first-term Democratic U.S. Sen. Al Franken is doing a good job, according to a new Star Tribune Minnesota Poll.

The 55 percent approval rating for the satirist-turned-senator matches a high-water mark reached last June, but the latest results also show a growing dissatisfaction with his job performance.

Franken's job disapproval rating has climbed to 34 percent, up from 29 percent last June.

The election that put Franken in office in 2008 was one of the tightest in the nation, with a victory margin of just several hundred votes over former U.S. Sen. Norm Coleman.

Since then, Franken has cultivated a low profile on Capitol Hill, opting not to capitalize on his fame from his days as a "Saturday Night Live" star and liberal radio host.

"He's already famous. He's not in it for that," said Jane Masterman, 49, a Woodbury Democrat who works as an administrative assistant for a Twin Cities nonprofit. "He's committed. He works hard. He listens to the little guys."

Not all Minnesotans agree, and some still harbor resentment from the 2008 election.

"I can't stand him. He got into office with a fake election," said Cheryl Kop, 62, a Moose Lake Republican and small-business owner. She considers him an out-of-touch liberal. "It's just a joke this state elected him," she said.

The poll, conducted by Mason-Dixon Polling and Research Inc., interviewed 800 Minnesota adults Feb. 10-12, by land line and cellphones, and has a margin of sampling error of plus or minus 3.5 percentage points.

Franken's job approval numbers are highest in the Democratic strongholds of Hennepin and Ramsey counties, where 68 percent approve of the work he has done in Congress.

"He's not treated this comically in any way," said Judy Parkin, 67, a St. Paul Democrat and social worker. "He has not been involved in the silliness of trying to shut down the government."

In the metro suburbs, Franken's approval stands at 58 percent. Outstate, however, his approval rating dips sharply to 42 percent.

Franken remains a polarizing figure, with job approval ratings of 97 percent from Democrats, but a 71 percent disapproval from Republicans. Both numbers have spiked since the last poll.

Independents are divided, but leaning against him, with 42 percent disapproving of the job he's done and 38 percent approving.

Bill Conlin, 47, is a Shoreview independent who voted for Franken in 2008 and is among the 38 percent of independents approving of Franken's work. "He's done a good job of trying to get himself in a position where he knows the issues," said Conlin, a business administrator.

Divergent paths

Franken was among the eight Democrats who captured Senate seats that had been in Republican hands when President Obama swept to election in 2008. Those senators are now defending themselves from attacks based on their support for the Affordable Care Act, Obama's health care law.

Obama and Franken's in-state political fortunes have diverged. Since a Minnesota Poll conducted in fall 2009, Franken's job approval rating has shot up 14 percentage points to 55 percent, while Obama's has fallen 7 points to 44 percent.

"Sen. Franken promised Minnesotans he would work hard for them every day, and that's what he's done," said Franken campaign spokeswoman Alexandra Fetissoff. "Minnesotans know he's kept his word and that he's going to keep fighting on their behalf."

Cambridge Democrat Christine Burlingame, 61, said Franken's push to restore emergency federal unemployment benefits has impressed her. She can relate to the thousands of Minnesotans whose benefits expired at the end of 2013. Burlingame now works in credit collections, but went through a 27-month period when she couldn't find a job.

"[Franken] just strikes me as being honest, and that can be a rare thing for politicians," Burlingame said.

Nicole Monaghan, 44, a Carver Republican, considers Franken an opportunist.

"It's all about Al, and isn't always about the people," said Monaghan, a homemaker and former social studies teacher.

Asked whether they had a favorable or unfavorable opinion of him, 38 percent of poll respondents view him favorably, but 30 percent view him negatively. Nearly a third are neutral.

Charles Shreffler, 58, a Bloomington Republican, has followed Franken's work on privacy issues.

"He's been a good advocate for citizens," said Shreffler, an attorney.

But Franken hasn't done enough to win over Shreffler, whose vote will to go one of four Republicans vying for the GOP nomination to take on Franken. "The Republican candidate is going to be closer to my fundamental beliefs," Shreffler said.

Conlin, the independent voter from Shoreview, said he faced a difficult choice between Franken and Coleman in 2008 and may encounter a similar dilemma this fall.

"I don't know who the Republicans are running against [Franken]," Conlin said. "I'll have to weigh my options. He's not a slam dunk."

Corey Mitchell is a correspondent in the Star Tribune Washington Bureau. Twitter: @C_C_Mitchell