Just like the influential conservative nonprofit that he runs, American Action Network Chairman Norm Coleman likes to fly below the political radar.

In contrast to GOP operative Karl Rove, who helped launch the American Crossroads super PAC and its affiliated nonprofit, Coleman is never blasted by Democrats railing against big money. Nor is he a favorite news profile subject, as is American Crossroads Political Director Carl Forti.

But the former Republican Senator from Minnesota is at the center of GOP fundraising, campaign strategy and policy from the top of the ticket on down in 2012. As chairman of both the AAN and its affiliated super PAC, the Congressional Leadership Fund, Coleman has been on the vanguard of raising and spending unrestricted money in the post-Citizens United era. He has the ear of presumptive GOP presidential nominee Mitt Romney, as a top foreign policy adviser to the former Massachusetts governor.

“Now that I’m not in the Senate, I’m really not looking for publicity,” admitted Coleman, 62, who co-founded the AAN in 2010 with Fred Malek, a longtime GOP operative who chairs the Thayer Lodging Group.

Coleman might not be able to avoid the spotlight much longer, however. The AAN is the target of not one but two IRS complaints by watchdog organizations that claim the group is violating tax law by spending most of its money on politics.

Coleman has dismissed the complaints as baseless and politically motivated. But Democrats have sought to make hay out of secret political spending with votes on disclosure legislation and letters to the IRS.

The IRS has signaled growing interest in politically active nonprofits, most recently announcing that it would “consider proposed changes” in tax exempt rules. And recently, a federal three-judge panel agreed with Rep. Chris Van Hollen (D-Md.) that groups running candidate-oriented issue ads on the eve of elections must disclose their donors.

All that may help explain why the American Action Network’s latest political campaign focuses on grass-roots, ground organizing, not broadcast ads. The group, which describes itself as a center-right “action tank,” will spend $10 million on a campaign to partner with local tea party and other allies on issues such as repealing the health care law and balancing the budget, said AAN President Brian Walsh, former political director of the National Republican Congressional Committee.

The AAN is also promoting its Hispanic Leadership Network, which will host a San Antonio, Texas, conference this month keynoted by Texas Gov. Rick Perry (R).

“We didn’t want to be simply a D.C.-centered operation,” Walsh said. “We wanted to find ways to go out into the country and start working with like-minded groups to build the grass-roots network that we think is necessary to compete with the left.”

Coleman’s operation will be running plenty of TV ads, too. Organizers confirmed reports that AAN and the Congressional Leadership Fund have reserved $3 million apiece on candidate advocacy ads in targeted House races. In the 2010 elections, the group spent $21 million on campaign ads and election-time candidate messages, according to the Center for Responsive Politics, making it one of the top three nonparty outside spenders that year.

This time, the group appears to be on track to spend even more, thanks in part to Coleman’s quiet tenacity as a fundraiser. Elected to the Senate in 2002 following a stint as the mayor of St. Paul, Coleman lost his re-election bid to Democrat Al Franken after a bitterly contested recount in what turned out to be the Senate’s most costly race.

“I think he’s a beloved figure in the donor community [of] Republicans and conservatives who are willing to make contributions to the cause,” said Mark Isakowitz, president of Fierce, Isakowitz & Blalock. A Romney campaign bundler, Isakowitz serves with Coleman on the board of the Republican Jewish Coalition, whose board also includes several top GOP super PAC and Republican Party donors such as casino mogul Sheldon Adelson, financier Lewis Eisenberg, hedge fund CEO Paul Singer and businessmen Sam Fox and Mel Sembler.

Coleman combines policy, political and fundraising savvy, said Americans for Tax Reform president Grover Norquist, who quipped: “How many can do all three?”

A member of the Foreign Relations Committee while on Capitol Hill, Coleman has a special focus on Israel and has appeared as a Romney surrogate on television and in Iowa, Florida and New Hampshire.

As a nonprofit, the AAN does not disclose its donors. But the Center for Responsive Politics has identified several through tax and other records. They include the Republican Jewish Coalition, which gave $4 million, and the Pharmaceutical Research and Manufacturers of America, which gave $4.5 million. Aetna also gave $3.3 million to ANN, according to recent disclosures.

The Congressional Leadership Fund has collected, by CRP’s tally, $6.5 million so far this cycle, thanks in part to the blessing of GOP leaders from Speaker John Boehner (Ohio) on down. Top super PAC donors include Texas home builder Bob Perry, who gave $1 million, and Adelson, who with his wife gave $5 million.

“I think it’s a new model, and I was blessed to be here at its inception. We caught the wave, and we navigated the wave, so that I think we’re in a position to have an impact,” said Coleman, who noted that he and Malek set out in part to create a policy counterweight to the left-leaning Center for American Progress.

Both Citizens for Responsibility and Ethics in Washington and Democracy 21 argue in their separate complaints to the IRS that the group is patently violating IRS law because it spends more than half its funds on political activity.

Coleman said the groups either “don’t understand the law,” or “mischaracterize it.”

“If we’re sending out a message to support lower taxes, or if we’re challenging somebody for supporting government-run health care, by law that is not political advocacy,” he said. “We are talking about policies.”