A small group of individuals, ­political organizations and unions dominate independent spending on Minnesota state elections, accounting for more than half of the $53 million donated to political action ­committees since 2007.

A Star Tribune analysis of ­campaign finance records found that just three dozen individuals or entities have contributed more than $27 million to political action and independent expenditure committees over the past three election cycles. The analysis shows those donations heavily favored Democrats. Unless that trend is reversed, Republicans could find themselves at a disadvantage heading into the 2014 elections, when they will attempt to retake the governor’s office and the Minnesota House.

One union — the powerful ­Education Minnesota teachers union — poured $4.8 million into ­election efforts, nearly all of it benefiting Democrats. Alida Messinger, a longtime DFL contributor and former wife of Gov. Mark Dayton, donated at least $1.6 million to Democratic political action committees.

On the GOP side, the ­Republican Governors Association, based in Washington, was a top donor, giving at least $2.4 million to GOP groups. Joan Cummins, wife of GOP heavyweight Bob Cummins, gave at least $1.2 million.

Since 2007, Democrats and their supporters consistently raised and distributed more money than their opponents. Even with the 2010 U.S. Supreme Court’s Citizens United decision, which allowed businesses to give money directly to political action committees, business interests and Republicans have not kept up.

“That’s not a surprise at all,” said Minnesota Republican Party Chairman Keith Downey. He acknowledged that in recent years, Democrats’ allies have had superior organization, a more energized base and campaign finance rules that he said make it easy for unions to contribute to politics.

Union donations dominate

The Star Tribune analysis of political donations and spending by independent groups — based on estimates because of flaws in the state’s electronic campaign finance database — illuminates the increasingly important role of political action and independent expenditure committees in Minnesota elections. The money flowing into and out of those outside committees is not controlled by candidates or parties, but it can help or hinder their chances for success.

In the last six years, union contributions dominated donations to state political action committees. State and national unions spent $17 million in ­Minnesota between 2007 and 2012. Businesses, newly empowered to spend after the Citizens United decision, directly donated about $3 million.

During that same period, business PACs spent about $8 million in state campaigns, and some of that benefited DFLers. Unions gave most of their money to labor-affiliated PACs, which in turn supported DFL candidates, campaigns and other Democratic groups almost exclusively.

Kris Fredson, political director at the Minnesota AFL-CIO, said money is an important supplement to other kinds of support.

“We do that kind of collective work with the boots on the ground, and we obviously do that with the financial contributions, too,” he said. “When it comes to the ­political programs, [unions] are all at the same table and we are all working together with ­common goals and priorities and ­programs.”

Businesses uneasy donors

In recent years, the state Republican Party has struggled with money and donor confidence, stemming in part from scandal and financial troubles that led to the abrupt departure of one party chairman.

In addition, Republicans and business interests have had to deal with corporations uneasy about aligning themselves with controversial issues that could alienate customers.

“Even though the stakes are high, the large public companies are very sensitive,” said Charlie Weaver, executive director of the Minnesota ­Business Partnership.

In 2010, Target Corp. faced a ferocious backlash from some of its customers because it contributed $150,000 to MN Forward, an independent campaign group Weaver helped run that was supporting GOP gubernatorial candidate Tom Emmer.

Meanwhile, the Alliance for a Better Minnesota, which supports DFLers, has become a national model for independent campaigning.

A coalition of Democratic groups and allies, the Alliance has taken in nearly $10 million since 2007, almost all of it from other political action committees. It has spent $7 million on Minnesota elections since then, making it the largest single spender among Minnesota political action and independent expenditure committees.

Fed by a money stream from unions, wealthy donors and national Democratic groups, the Alliance donates little to others. Instead, it spends it on polling, advertising, mailings and staff who have a single goal: Elect Democrats.

Carrie Lucking, Alliance’s executive director, said she already has begun talking to local and national groups about next year.

“We are very focused on winning the governor’s race and making sure that we retain a middle-class majority in the House,” she said. Although donors will not give formal financial commitments until 2014, she said it is clear that supporters want to make sure that Minnesota’s status as a “progressive island” in a sea of GOP-dominated states is rewarded.

That strategy has worked in the past. Concentrated ­spending by the Alliance helped send Mark Dayton into the governor’s office in 2010, making him the state’s first DFL governor since Rudy Perpich left office in 1991. Last year, the Alliance contributed heavily to the avalanche of outside spending that transformed many legislative races from low-dollar affairs into six-figure contests and subsequently gave DFLers control of the state House and Senate.

The Alliance is closely connected to the state’s most generous political groups and individuals. The same union and individual donors that rank in the top three dozen givers statewide contributed heavily to the two groups that fund the Alliance, WIN Minnesota and the 2010 Fund, which became the 2012 Fund. Those funders, in turn, got much of their money from the Democratic Governors Association; Education Minnesota and other unions; and Messinger and other wealthy Minnesotans, some with the last name Dayton.

GOP, business interests coalesce

GOP-favoring committees spent as much as the DFL-supporting Alliance over the past six years and share many big donors among themselves. But even though those groups, and their donors, often have close relationships and ­discuss strategy, they did not pool their money as the Alliance did. Instead, they largely spent separately, diffusing the power of their cash.

After seeing the Alliance at work, some say they will try to build an Alliance-like coalition on the Republican side in 2014.

“We’re going to be working together,” said Weaver of the Minnesota Business Partnership. He’s also the treasurer of MN Forward.

MN Forward tried to create such a coalition in 2010, taking donations from TCF Bank, Target, Best Buy and the Minnesota Chamber and fusing them into a $1.4 million pool it could spend to help elect Dayton’s opponent, Emmer, a former state representative. ­Target’s experience put a chill on the group and it has spent little since then.

Weaver said that in the future, businesses here will focus less on individual candidates and more on advocating for a job-growth-friendly environment in Minnesota.

He and others speak with admiration about the Alliance’s efforts — and a touch of envy.

“They are very, very well organized,” Weaver said. “We look at what the Alliance did in the last election [and] … we are trying to be as effective as they were.”

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Interactive: Click here to see the relationships among Minnesota's top political donors.