ROCHESTER – Gov. Mark Dayton and Republican challenger Jeff Johnson finally met face-to-face Wednesday night, clashing over the incumbent governor's leadership in the past four years and Minnesota's priorities in the next four.

Dayton, Johnson and the Independence Party's Hannah Nicollet kept the tone largely cordial in the 60-minute debate at Mayo Civic Center, the first of this year's campaign. Johnson struck the most aggressive tone, with a litany of criticism aimed at Dayton's record, though he kept fuzzy on details of how he'd rein in state spending if elected.

Seeking a second term, DFLer Dayton mostly avoided direct engagement with Johnson's jabs. Instead he touted highlights from his time in office: an increase in the number of jobs, a lower state unemployment rate, and high-profile projects like Rochester's own Destination Medical Center, a public-private partnership with Mayo Clinic to remake the city's downtown.

"There was a $6.2 billion deficit when I took office," Dayton said. "The fiscal situation of the state at that time was dire. Now we're looking at a surplus."

Typical of Johnson's wide-ranging criticism of Dayton were his harsh words about MNsure, Minnesota's health insurance exchange, which released 2015 rates earlier in the day that revealed Minnesota on average will continue to offer the lowest premium costs in the country. Johnson took issue with Dayton's measured praise for the program, which stumbled in its launch last year.

"We had the best insurance in Minnesota, and we don't anymore," Johnson said. "It's been an unmitigated disaster and it's hurting thousands of people."

For Nicollet, a virtual unknown running with little left in campaign funds, the debate was a rare chance to make a wider impression. She said being an outsider would make her a good governor.

"If you're an abused child, you shouldn't need a high-paid lobbyist to represent you at the Capitol," Nicollet said. "In my administration, you wouldn't."

The debate spun quickly through a number of issues, with the candidates taking on topics such as jobs and the economy, transportation and local government funding.

Playing to the hometown crowd, Dayton emphasized his early support for the Rochester medical center project. At his urging, the Legislature approved $455 million in state funds to help leverage nearly $6 billion in private investment. Mayo Clinic estimates it will create 30,000 new jobs.

"It's a phenomenal project for Rochester, for the state of Minnesota, and should it be a model for the rest of the state? Absolutely," Dayton said.

Johnson seized on recent revelations of some technical blunders with the legislation that authorized the project. Dayton said the problems were minor and easy to fix, but Johnson called it an example of Dayton's mishandling of high-profile issues.

"It's never an easy fix when you're dealing with something controversial," Johnson said. He called the project "good for Rochester and good for Minnesota."

After the debate, the Minnesota DFL pointed out that in August 2013, at a State Fair forum for Republican gubernatorial candidates, Johnson said he would have voted against Destination Medical Center funding had he been in the Legislature.

Johnson, a Hennepin County commissioner, also went on the offensive over plans by PolyMet Mining Corp. to open a copper and nickel mine in northern Minnesota. Johnson charged that Dayton's administration has purposely moved slowly toward final approval of a project that promises up to 360 full-time jobs and many more temporary ones.

"I don't think PolyMet will ever open if the governor is re-elected," Johnson said. "I will do everything I can to get it open."

While the federal Environmental Protection Agency gave the project a passing grade earlier this year, with some conditions, the state Department of Natural Resources is still working on an environmental impact statement.

"To jump in while the environmental impact statement is fairly close to completion, and to forget about environmental considerations, to pander to northern Minnesota, I think is really irresponsible," Dayton said.

Patrick Condon • 651-925-5049