Minnesotans who fret that increasingly negative, hyperpartisan politics will repel good people from elective office have a new case in point: Duluth Mayor Don Ness cited his distaste for today's politics as he explained his decision Monday not to seek a third term.

Ness has been an exceptional mayor of Minnesota's fifth-largest city. He rallied the city after a major flood in 2012 and led recovery measures that minimized its damage to the city's expanding economy. His credits also include stabilizing a shaky city budget, reducing the unfunded liability in a city retiree health care plan, eliminating sanitary sewer overflows into Lake Superior and bolstering city parks.

At only age 40 and so popular that in 2011 he became the first mayor in city history to run unopposed for re-election, Ness appeared headed for a long career in public service. Seeking a third term would not have been unusual among Minnesota's best mayors — witness the three-term service of Chris Coleman in St. Paul, Ardell Brede in Rochester, and R.T. Rybak in Minneapolis, and even the four-term service of Gene Winstead in Bloomington. Ness was also frequently mentioned as a future DFL candidate for Congress or governor.

But Ness said Monday that while he loved the policy challenges and service opportunities he seized as mayor, he has grown impatient with politics. He worries about his ability to shield his three children — ages 9, 7 and 3 — from the worst of it, he told the Duluth News Tribune.

As for higher office, Ness told MPR's Cathy Wurzer that "more likely than not, this will be the last political office that I run for. … When I start to think about a role at either a state or national level, it becomes much more partisan. It becomes much more of that base politics that I don't enjoy. It's unlikely that I would do that, at least until my kids are out of school and on their way."

Wisely, Ness did not say "never" about a future political bid. We hope he warms to the idea one day. He argued as he announced his decision on Facebook that Duluth does not need him in the mayor's office to continue to prosper. Perhaps not — but Minnesota needs leaders of his caliber, and it's a worry to see one so able turned off by the political gantlet one must run in order to serve.