(CNN) - President Barack Obama's re-election campaign filed a complaint Tuesday, claiming a conservative group founded by Karl Rove is in violation of election law by not disclosing its donors.
In a letter to the Federal Election Commission, a lawyer for Obama's campaign argued that Crossroads GPS is a political committee–not a charitable organization–and therefore should meet disclosure requirements.
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"There has never been any doubt about its true purpose: to elect candidates of its choice to the Presidency and the Congress. Under the pretense of charitable activities, Crossroads has tried to shield its donors–wealthy individuals, and corporations who may be pursuing special interest agendas that are not in the national interest," wrote Robert Bauer, the attorney, in the letter.
Crossroads GPS is the private arm–a 501(c)(4) organization–aligned with American Crossroads, a so-called super PAC.
While non-profit groups, like Crossroads GPS, report to the IRS and are not required to disclose its contributor list, super PACs, like American Crossroads, report to the FEC and are required to do so.
As a private entity, however, Crossroads GPS has to live by different rules. More than half of its ads can't be explicitly political, meaning it has to walk a fine line by promoting a specific issue rather than focusing solely on a specific candidate.
For example, these ads can eviscerate Obama as long as they attack him on a specific policy. Last summer, the group ran an ad, "Wake Up," featuring a woman feeling concerned about the economy and questioning whether Obama could help the situation improve.
"Our country's got this huge debt. But Obama says raise taxes and keep spending more?" the woman in the ad says. "There's got to be a way to take away President Obama's blank check."
Of late, Crossroads GPS and American Crossroads have particularly focused on Senate races. The two groups announced this month a $4.6 million ad buy with spots targeting Democrats in six states with high-profile Senate races.
The outside spending groups have already spent millions more this cycle and have previously stated they hope to raise a combined $300 million by November.
But Obama's team argues the ads that Crossroads GPS has produced indicate the group operates more like a political committee than a private, charitable organization.
"Complaints about this scheme to achieve anonymity are pending before this agency and before the Internal Revenue Service, but Crossroads seems to believe that it can run out the clock and spend massive sums of money in this election without accounting for a trace of its funding," Bauer wrote.
Responding to the complaint, Crossroads spokesman Jonathan Collegio described it as a "goofy sideshow" and pointed to a group supportive of the president.
"Folks would do well to consider this a goofy sideshow until Obama sends the same letter to Priorities USA - the group modeled after Crossroads but which supports the president. Obama doesn't care about the campaign laws; he only cares about silencing conservative groups that are holding him accountable for his failed record," Collegio said.
Priorities USA, the pro-Obama group, is also a 501(c)(4) non-profit group that is not required to disclose its donors. Similarly, it's connected to a super PAC, Priorities USA Action, to which the Obama campaign has urged donors to contribute.
- CNN's Ashley Killough, Kevin Bohn and Jessica Yellin contributed to this report.