MINNEAPOLIS (AP) _ The first time Norm Coleman went up against a celebrity for statewide office, he was slammed by former pro wrestler Jesse Ventura.

Coleman did better against his second famous opponent, edging former Vice President Walter Mondale to win his seat in the U.S. Senate. He's hoping to repeat that success in his third run against a well-known name in as many tries Democrat Al Franken, the former "Saturday Night Live" comedian and radio host.

Coleman has become one of the state's most recognizable politicians. But in preparing for his latest fight, Coleman has tried to turn the spotlight back on Franken, criticizing some of the more outrageous or profane things he's said or written in years of comedy routines and liberal commentary.

"If the partisan disease is what's tearing Washington apart, for years he was part of that," said Coleman, who officially launches his campaign Wednesday. "The talk radio culture, the Rush Limbaughs, the Ann Coulters, the Al Frankens. If that's the disease, I've tried to be the cure to that disease for a long time."

Coleman said Franken wouldn't be able to "work across the aisle with people he has so ridiculed and so debased."

Coleman's political survival could depend on whether he can convince swing voters that Franken lacks the temperament to be a senator. Coleman is a Republican senator in a Democratic-leaning state, and Minnesota's race is at the top of the list of those Democrats believe they can win in 2008.

Franken, heavily favored to be the Democratic nominee, said Coleman often sounds more like a challenger than incumbent. Franken defended his previous work as that of a satirist.

"I'm not going to play their game," Franken said. "They're going to take things I said completely robbed of their context, and I'm not going to address each one."

Democrats say Coleman's tributes to bipartisanship and moderation are hypocritical, arguing he spent his first few years in the Senate as a close ally of President Bush, whose popularity remains low.

Given Franken's celebrity and both candidates' proven ability to quickly raise millions of dollars, political observers expect the nastiest and most expensive political contest ever in Minnesota.

"I think by October, a bathtub is the only thing you'll be able to turn on without hearing Norm Coleman and Al Franken attack each other," said Tom Horner, a PR executive and former Republican strategist who advised Coleman in his failed 1998 bid for governor.

Coleman is no stranger to wild campaigns. First elected mayor of St. Paul in 1993 as a conservative Democrat, he switched to the Republican Party three years later. Many Democrats have resented him ever since.

Coleman was reelected mayor as a Republican and appeared headed for the governor's mansion in 1998, only to be routed by Ventura's unlikely political ascent.

After a brief stop in the private sector, Coleman returned to politics in 2002 when he agreed at President Bush's request to challenge Sen. Paul Wellstone. After Wellstone was killed in a plane crash less than two weeks before the election, Coleman went on to defeat Mondale, the Democrats' last-minute replacement. That earned Coleman another demerit from Democrats who think he benefited from tragic circumstances.

"I think there is a slightly elevated level of blood pressure to beating him than we'd see for other Republicans," said Brian Melendez, the state Democratic Party chairman.

Democrats and Republicans agree that the fight for Coleman and Franken is over the roughly 40 percent of voters who aren't reliable Democrats or Republicans. Despite Minnesota's longtime preference for Democratic presidential candidates, voters have consistently elected both Democrats and Republicans to statewide offices.

Coleman is touting his effectiveness as a dealmaker and negotiator, trying to make voters recall his accomplishments in St. Paul. In an interview, he referred to himself as "Minnesota's mayor in Washington." Coleman said it's possible to be a loyal Republican when it's called for but still work with political opponents on shared goals.

That's something Franken won't be able to do, he argues.

"What is there in his life experience that shows he's actually qualified to work in the Senate?" Coleman said.

But every time Republicans air another of Franken's intemperate comments, expect Democrats to hit back with an example of Coleman praising Bush or his policies.

"It's not enough that Bush is going to go in 2009," Franken said. "His enablers have to go too."

Copyright 2008 The Associated Press.