It took Mark Dayton two tries and many millions from his personal fortune to win one of Minnesota's U.S. Senate seats. After one frustrating term, he couldn't wait to flee Washington.

Three years later, Dayton is trying to revive his political career _ this time as a candidate for governor pushing unabashedly for a tax increase and disclosing bouts with depression and alcoholism.

He hopes to claw his way through a field of 11 Democrats to face challengers from the Republican and Independence parties in November. GOP Gov. Tim Pawlenty passed on a third-term bid as he weighs a possible run for president.

Dayton steps up his campaigning in January _ just as he turns 63 _ by visiting all 87 Minnesota counties in 87 days. Early on, he'll hit the bone-chilling northern counties bordering Canada.

"If you go in the summertime, they know you're interested," Dayton said. "If you go in the wintertime, they know you're serious."

Seriousness is what Dayton is about. He often comes off as stiff in front of a crowd, and has never been known for smooth oratory or political flash. Dayton wants voters to see him as an earnest leader capable of tackling Minnesota's monumental budget problems in a shaky economy.

But he brings a lot of baggage to the race.

With his Senate term set to expire after 2006, Dayton opted against running for re-election amid faltering poll numbers and fundraising difficulties. The department store heir had sunk $12 million into his 2000 campaign, and had no plans to dig that deep again.

He left with a jaded view of the Senate and his place in it. He called Washington a "cesspool" and told a group of students that Congress, including himself, deserved "an F for results." Outsiders graded him just as harshly: Time magazine labeled him "The Blunderer" on a list of ineffective senators, citing his widely criticized decision in 2004 to temporarily close his Senate office over fears that terrorism endangered his staff and visitors.

The lowlights have overshadowed what Dayton regards as the successes of his tenure, from securing money for a pioneering mental health program for soldiers returning from combat to setting up a hotline for people denied claims by their insurance companies.

"I stand on what I was able to accomplish and acknowledge I couldn't accomplish as much I wanted to because of the limitations of being low in seniority and being in the minority," he said in an interview. "For those very reasons I wanted to seek a position where I could be effective."