Unlike candidates, the groups face no limits on how much money they can raise or where the cash comes from.

Outside groups have spent tens of thousands of dollars on legislative races scattered across Minnesota, according to campaign disclosure reports posted Wednesday that signal a possible roadmap to some of the most competitive fall campaigns.

Unlike candidates, the groups face no limits on how much money they can raise or where the cash comes from. Their only constraint is that they are prohibited from coordinating spending with candidates.

Some of the heaviest spending, according to the most recent reports, came in closely contested races in Woodbury, Eagan, Northfield, Rochester and hot spots in northern Minnesota.

The spending is coming from Republican allies defending the current GOP legislative majorities and Democratic-friendly groups trying to overturn those majorities. The party that controls the Legislature after the election will set the agenda for the second half of Democratic Gov. Mark Dayton's term and determine how far Dayton gets with campaign promises to raise top-level income taxes and send more money to schools.

Top races include:

—In Woodbury, the business-backed Pro Jobs Majority and conservative Freedom Club State PAC together spent more than $42,000 in recent weeks on mail pieces supporting first-term Republican Sen. Ted Lillie, who faces a challenge from Democrat Susan Kent. That's after the Democratic-backed Alliance for a Better Minnesota early this summer spent almost $13,000 on mail opposing Lillie.

—Pro Jobs Majority and the Freedom Club spent more than $42,000 combined on mail for first-term GOP Sen. Ted Daley in Eagan, who faces a rematch with former Democratic Sen. Jim Carlson. The Service Employees International Union Minnesota State Council has put nearly $2,000 into phone banking and voter outreach for Carlson.

—The Freedom Club and Pro Jobs Majority together have spent almost $42,000 for Republican Mike Dudley for an open Senate seat in Northfield. Dudley faces former Democratic Sen. Kevin Dahle, who lost the seat in 2010.

—In a far northern Minnesota House district that includes Lake of the Woods and Beltrami counties, the Coalition of Minnesota Businesses PAC earlier this month spend $3,720 on mail supporting Republican Rep. David Hancock. Hancock was the target of about $13,000 in negative mail funded by the Alliance for a Better Minnesota in May and June. He faces a challenge from Democrat Roger Erickson.

—An open House seat in Moorhead is drawing spending by the Minnesota Business Partnership PAC and Minnesota's Future, a conservative group. Since August, they have spent more than $13,000 combined on mail supporting Republican Travis Reimche, who faces Democrat Ben Lien.

—Two Rochester House races have drawn more than $14,000 each from Pro Jobs Majority. The group is supporting Republican Breanna Bly over Democratic Rep. Tina Liebling, a four-term incumbent. It's also backing first-term Republican Rep. Mike Benson, who is up against Democrat Pat Stallman.

Meanwhile, the Alliance for a Better Minnesota reported spending more than $650,000 through Sept. 18 on TV ads slamming Republicans who control the Legislature. The group gets its money from two funds supported by wealthy donors and labor unions. Together, WIN Minnesota and the 2012 Fund had about $1 million on hand.

Collectively, Pro Jobs Majority, the Minnesota Business Partnership PAC, the Coalition of Minnesota Businesses PAC, Minnesota's Future and the Freedom Club State PAC had nearly $1.2 million left to spend. Major donors included Hubbard Broadcasting, the Minnesota Chamber of Commerce and Starkey Hearing Foundation founder William Austin.

The reports also showed the role outside groups played in two Republican legislative primaries that resulted in the defeat of incumbents in the suburban Lake Minnetonka area.

The Freedom Club State PAC spent more than $55,000 opposing Republican Rep. Connie Doepke and supporting conservative opponent Dave Osmek in a primary for an open Senate seat. The Minnesota Business Partnership PAC and Pro Jobs Majority together spent $5,700 supporting Doepke, who lost narrowly.

In a House primary, Freedom Club State PAC and Minnesota's Future spent more than $52,000 promoting tea party Republican Cindy Pugh and opposing GOP Rep. Steve Smith, a 22-year incumbent. Labor unions donated to a group called Citizens for Smith, which together with AFSCME Council 5 spent more than $10,000 supporting Smith. Pugh won in a blowout.

The spending on legislative races is dwarfed by the money going into a ballot question on a constitutional gay marriage ban.

The pro-gay marriage group Minnesota United for All Families reported raising about $2.56 million since the last report in late July, while Minnesota for Marriage, which favors the gay marriage ban, brought in about $560,000. The Minnesota Catholic Conference has chipped in about $600,000 this year in support of the gay marriage ban. Minnesota United had $750,000 in the bank on Sept. 18, compared with about $484,000 for Minnesota for Marriage.