Brown and Warre are both calling for outside groups to stay off the airwaves. | AP Photos Brown, Warren to super PACs: Quit it

BOSTON — Democratic candidate Elizabeth Warren and Republican Sen. Scott Brown on Monday demanded a cease-fire of the third-party spending that’s certain to play a major role in this state’s pivotal Senate race.

Senior officials from Brown’s and Warren’s campaigns will soon meet to try to craft an unusual pact to curtail the influence of so-called super PACs that have grown in power since the Supreme Court’s Citizens United case loosened campaign finance rules in 2010.


Whether the talk amounts to anything more than public posturing to distance themselves from the millions of dollars in negative attacks launched by the groups remains to be seen. Experts are skeptical that groups will unilaterally disarm knowing that this race could tip the balance of power in the Senate.

But Brown and Warren — both of whom will have war chests flush with their own campaign cash — are trying to make the case that they want outside groups to stay off the airwaves, in a bid to appeal to voters tired of partisan mudslinging.

“What I’d like to do is I’d like to be able to run my campaign,” Warren said before a Martin Luther King Jr. Day event at this city’s convention center. “I’d like for Sen. Brown to run his campaign and we both be responsible for what is said. I think that is the right way to be able to run the campaign.”

Brown, speaking outside an American Legion post in Mattapan, Mass., said he’s “glad professor Warren seems to be coming around on this issue,” adding that he’s been calling on her to disavow outside spending for several weeks.

“I think by sending a joint message to stay out, I’m hopeful they’ll accept that message,” he said. “This is going to be decided by the people of Massachusetts, not by the tens of millions of outside interest dollars coming into our state.”

Federal law precludes the campaigns from coordinating with the outside groups, which have already spent at least $3.5 million across the airwaves here. But Warren said Monday that the campaigns could agree on a common response if third-party groups become active on the airwaves and ignore their demands.

“That’s certainly within our control,” she said.

The back-and-forth started Friday, when Warren responded to Brown in a letter saying she wanted to create an “enforceable” pact to seek an end to radio, TV and online advertisements by outside groups, saying there should be “consequences” for the campaign that does not honor the agreement. The two spoke later that day, and their campaign managers are talking Tuesday about setting a time for a future meeting.

Asked Monday if she could lay out consequences for not adhering to any agreement, Warren would only say that she wants “something that actually means something. No more politics as usual.”

Warren later said in an interview that her call for outside groups to stop spending in her state includes the National Republican Senatorial Committee and the Democratic Senatorial Campaign Committee.

Rick Hasen, an election law expert, said outside groups would have “no incentive” to stop pouring money into the state, given the high stakes of what will be a closely contested race.

Indeed, outside groups on both sides were non-committal when asked about the candidates’ rhetoric on Monday.

“We don’t discuss strategy of specific races,” said a spokesman for the GOP-aligned American Crossroads on Monday.

Similarly, the liberal League for Conservation Voters — which has already been active in the state — wouldn’t say whether it would stay out of the race.

“We’ll take the candidates’ public statements on the subject into account as we look ahead to the 2012 election, but our responsibility is to our 400,000 plus LCV members and the environment,” said Navin Nayak, the group’s senior vice president for campaigns.