If you live in Florida, Ohio, Montana, or Missouri, you’ve probably seen attack ads from the 60 Plus Association, a group that touts itself a “non-partisan seniors’ advocacy group” and the “conservative alternative to the American Association of Retired Persons (AARP).” Senator Sherrod Brown (D-OH) alone has faced $2.3 million in ads all financed by the group. The avalanche of ads against Democratic incumbents in these four states is a repeat of 2010, when the group mysteriously raised many millions to take downDemocratic House members in districts across the country.

No one knows exactly where the 60 Plus Association, a 501(c)4 nonprofit entity, gets its money. After the Citizens United decision, the group became a favored front for GOP operatives, including attack-ad specialist Carl Forti, to pummel the opposition. Forti told Slate.com’s Dave Weigel that the group only receives money from its senior membership base:

“There are five and a half million supporters of 60 Plus,” said Carl Forti, who handles the group’s PR and media activity and once worked for the National Republican Congressional Committee. “And that’s where the funding comes from.

The claim that 60 Plus is merely a member-support seniors’ advocacy group, however, was undercut by the group’s president Jim Martin in an interview with Republic Report last week. Martin told us that he expects Charles and David Koch, among other wealthy donors, to fund his organization this year. A non-profit corporation set up by Sean Noble, a political operative working for the Koch brothers, secretly funneled $11.6 million to 60 Plus in 2010 for ads against Democratic politicians.

Asked about the money flowing to the 60 Plus Association from billionaire corporate titans, Martin was nonplussed that the identity of his benefactors might conflict with the public image of his organization. “I don’t know if they’re all seniors or not, but I would assume some of them are, thank goodness,” said Martin, who spoke to us at the Faith & Freedom Coalition conference hosted by evangelical lobbyist Ralph Reed.

Moments later in our interview, Martin conceded that he encourages direct corporate donations to his group:

FANG: But now, corporations can give to your group.

MARTIN: Absolutely.

FANG: And you encourage that?

MARTIN: Oh lord, put it in my name and address and mailing address. I encourage you to do that so they can send me donations! What’s wrong with that? What’s wrong with that? What’s wrong with it?

FANG: But your group says, on your ads that they represent people, seniors. Are corporations people? Are they seniors?

MARTIN: Hah, go ask Governor Romney. Don’t go there with me, young man.

Martin changed the subject, but later told us an anecdote about his interactions with party committees. Martin asked where Republic Report’s Zaid Jilani had graduated from college. After hearing that Jilani went to the University of Georgia, a rival of Martin’s University of Florida alma mater, he told us a story. Martin said that during a meeting with the National Republican Campaign Committee, the Republican Party arm devoted to electing candidates to the House of Representatives, he jokingly told a prospective candidate for office that he wouldn’t run ads to support her given her husband’s relation to the University of Georgia football team. The woman, Martin laughed, turned purple with embarrassment before Martin assured her that he was only kidding. He said he promised the ads to the candidate anyways.

Martin, who has adamantly reminded the press that his group is independent, seemed to let slip that his group coordinates with both the Republican Party and candidates on election spending. Current campaign finance law prohibits such coordination.

Martin maintains a low profile, but his group has been pivotal in shaping who is elected to Congress. Martin himself is a longtime GOP campaign hand. And he is well-known within the incestuous world of Alexandria-based media consultants. (60 Plus Association shares offices with political consultants who manage more infamous Super PACs including Mitt Romney’s Restore Our Future and Karl Rove’s American Crossroads.) As Martin likes to remind people, he was even responsible for giving George W. Bush his first campaign job back in the early 1960s.