Sen. Scott Brown (R-Mass.) has offered his Democratic rival a creative way to dispose of the outside groups who have pledged to spend millions in his Senate race.

The first-term senator wants both campaigns to commit to donate half of whatever outside groups spend to a charity of their opponent’s choice.

{mosads}The novel, unprecedented nature of the proposal raises the curtain on the chaos that has afflicted campaigns in the wake of the 201 Citizens United Supreme Court decision that allowed funds from outside groups to flood into House, Senate and presidential races.

Both Brown and Elizabeth Warren, the Democratic front-runner seeking to unseat Brown in November, have been hit by attack ads aired by groups that their campaigns don’t control and with whom they cannot — by law — coordinate.

Crossroads GPS, a deep-pocketed group founded by Karl Rove, has attacked Warren in ads tying her to violent elements of Occupy Wall Street, while the League of Conservation Voters has knocked Brown in ads portraying him as an enemy of the environment.

Brown has long decried the spending on both sides, and has called for Warren to join that cry in an attempt to stymie groups on both sides from muddying the waters. Warren joined that call last week when she proposed a meeting between the two candidates’ campaign managers to craft an “enforceable agreement” to rein in outside groups.

The freshman senator unveiled his proposal for such an agreement on Wednesday, telling Warren in a letter obtained by The Hill that all that is needed to get something done for Massachusetts is her signature.

“The agreement’s terms are simple: My campaign will bear a steep financial penalty if third party ads are run supporting me or opposing you, and vice-versa,” Brown wrote. “No gimmicks, no fine print, no legalese.”

In an accompanying pledge — signed by Brown on Wednesday — the senator lays out the details: explaining that if any third party organization airs an independent expenditure ad on broadcast, cable, satellite television or online, the candidate benefiting from the ad will have three days to donate 50 percent of the cost of the ad to a charity chosen by the opponent.

The agreement would apply both to positive ads praising a candidate and attack ads undercutting his or her opponent. The pledge also refers to ads “in support of or in opposition to candidates,” language that has
historically referred to electioneering ads that explicitly support a
candidate for office.

But the specifics may provide a loophole for the outside spending groups.

“Pathetic, crazy times call for pathetic, borderline crazy measures. This seems to be one such measure,” said Paul S. Ryan, an attorney for the nonpartisan Campaign Legal Center.

He pointed out that the specific reference to independent expenditures and to ads “in support of or in opposition to” — would likely prevent the agreement from effectively curtailing outside spending.

The pledge likely wouldn’t apply to the more ambiguous issue ads that, for example, warn voters about how terrible the candidate’s record is without overtly telling people to vote for or against the candidate.

“I would expect to see hard-hitting, sham or maybe even legitimate issue ads having just as much impact as the independent expenditures,” Ryan said.

That exception could allow super PACs and outside groups to find a way to blanket the airwaves without violating the letter of the Brown-Warren agreement, if one comes to fruition.

Warren’s campaign appeared to have picked up on that nuance, asserting in a response to Brown’s letter that the two candidates should go beyond Brown’s proposal, and offered a clause of her own: “Ensuring that the agreement not only cover express advocacy ads, but all paid public advertisements that seek to promote or attack either candidate or campaign.”

Warren also suggested that radio ads be added to the mix, and that the two candidates jointly reach out to area broadcast outlets to urge them not to air ads that violate the agreement.

A Brown aide said that Jim Barnett, who runs Brown’s campaign, and Mindy Myers, who heads Warren’s campaign, are scheduled to meet on Friday to hash out a plan.