Throwing the bums out is becoming a popular pastime in the newly competitive Minnesota Legislature, and Rick Olseen and Sean Nienow have both been throwers and throwees.

Now, as they look toward a third race next year, Republican Sen. Nienow and former DFL Sen. Olseen wonder which party will be on the throwing end in 2012. A dramatic sweep by Democrats in 2006 brought in Olseen. A historic win by Republicans last year unseated Olseen and installed Nienow.

Their northern exurban district, along a growing I-35 corridor from Wyoming to Rush City, is one of many battlegrounds in what had been a true-blue state Senate. In DFL hands from the Vietnam War era through the emergence of the Tea Party, the Senate is now part of a larger struggle for Minnesota's political future.

The intense fight for control of that future is already underway, more than a year out. Knowing that even a one-vote majority could profoundly change state policies, both sides are busy this fall recruiting new candidates, stockpiling money and honing their arguments to fit the times.

"It used to be, the sun rises in the east and the Democrats control the Senate," said Steven Schier, political science professor at Carleton College. "That correlation has dissolved."

DFLers took control of the 67-member Senate in 1973 and never let go until last year, when Republicans ousted 13 DFL incumbents, gaining a historic seven-vote majority. By comparison, the 134-member House shifted power five times and tied once in that same period.

Recent Senate swings have been dramatic. In 2006, when President George W. Bush was weakened by the Iraq war and Hurricane Katrina, Senate DFLers capitalized on voters' anger to gain a 21-vote majority. Four years later, following the debate over President Obama's health care bill and Tea Party activism, Minnesota Republicans returned the favor, and the percentage of re-elected Senate incumbents was the lowest in four decades.

"In 2006 all the swing districts came our way. In 2010 they went their way," said Senate Minority Leader Tom Bakk, DFL-Cook. "What kind of message comes out of Washington, D.C., has an awful big impact on people."

Eagan Mayor Mike Maguire, a DFLer who hopes to unseat a Republican Senate incumbent in next year's election, said that "It seems like every year is a throw-the-bums-out year."

The coming Senate clash is complicated by legislative redistricting, the every-10-years redrawing of districts to account for population shifts. A court-drawn plan will not be ready until Feb. 21, but all House and Senate incumbents must run in the new districts in November 2012. More wild cards: A new state revenue forecast in early December, a legislative session that begins in late January, and what promises to be a fever-pitch presidential race at the top of the ticket.

"We're about two-and-a-half lifetimes away from the next election," said Nienow.

In fact, the race begins Tuesday, with special elections to fill vacancies in south Minneapolis and Brooklyn Park, both seats long held by DFLers.

A tale of three districts

Three districts in particular show how far the Senate has moved from being safe DFL turf.

Senate District 17, which spreads from Interstate 35 north of Wyoming, was where Nienow, a financial adviser and consultant, unseated a DFL incumbent in 2002 only to lose in 2006 to Olseen, a trucking repair estimator. Nienow roared back in 2010, defeating Olseen by 12 percentage points. Both expect a rematch in November 2012. Nienow says he has been attending town-hall meetings to explain Republican policies and Olseen has been holding his traditional pig roast fundraisers, keeping the head attached because "the kids love that."

In Eagan's 38th District during the same period, the seat switched from DFL to GOP in a razor-close race in 2002. Retired engineer Jim Carlson won it back for the DFL in 2006, but lost to Republican accountant Ted Daley in 2010. Carlson and Mike Maguire, the Eagan mayor, both want to challenge Daley next year.

Out in the west-central 10th District, which is closer to Fargo than to St. Paul, DFLer Dan Skogen, a radio broadcaster who goes on the air to "make fun of the person I became," unseated a longtime Republican incumbent in 2006. Skogen fell to Republican Gretchen Hoffman, a nurse and businesswoman, in 2010. Both plan to run again this year.

"People think government has grown out of proportion to where it belongs," said Hoffman. Skogen: "People are anxious -- the recession is the real deal."

The bitter backlash from the state's 20-day shutdown this summer, a ballot question on gay marriage and the possibility of large property tax hikes will figure into talking points and brochures.

Senate Majority Leader Amy Koch, R-Buffalo, says her side's message will be simple. "The private sector is what grows jobs," she said. "We have to talk about what government does to hinder job creation ... such as regulation, permitting, and an unfriendly tax climate." Koch is credited with recruiting the Republicans who helped win the majority.

Bakk said the DFL will focus on what they consider the Republicans' gimmicky budget solutions -- particularly if there is further budget trouble. "Are we going to borrow more from schools?" he asked.

Nienow will remind voters that they need legislators who will keep a foot on the spending brake and resist tax hikes in the midst of a recession. Olseen, his likely opponent, said he will zero in on the Legislature's decision to borrow heavily from schools to balance the budget, and will argue that the GOP-controlled Legislature failed to deliver on a promise to create jobs.

With such a narrow margin in the Senate, a swing of four seats could tip power back to the DFL. Republicans will be trying to defend first-termers in swing seats -- many in suburban areas -- and to attack in areas where they came close in 2010, such as the east metro seat held by DFL Sen. Katie Sieben of Newport.

For minority Democrats, the goal is to recruit credible challengers, find a consistent and marketable message, and compete aggressively in up-for-grabs suburbs such as Eagan and Woodbury.

Complicating their efforts, both parties will have to reshuffle all the cards once the new district maps come out in February.

Buffeted by national trends and responsive to public mood swings, the Minnesota Senate is likely to remain a more dynamic and less comfortable place to be. "It used to be, all politics is local," Olseen said. "Now it's almost going the other way. If people aren't supportive of who's at the top of the ticket, it trickles right down to the bottom."

Jim Ragsdale • 651-925-5042