Warren, Brown debate reveals more friction to come in Massachusetts Senate race

Both cheers and hisses filled the debate hall at the University of Massachusetts Lowell on Monday night, most loudly when Republican Sen. Scott Brown jabbed at Democratic challenger and Harvard law professor Elizabeth Warren after she interrupted his answer about a jobs bill.

"Excuse me, excuse me, I'm not a student in your classroom," Brown quipped, to an uproar from both supporters and detractors in the audience. It was the edgiest moment of a debate—the second of three—full of needling, accusations and, when host David Gregory asked the candidates to reflect positively on the other, open sarcasm.

Until recently, this tight race stood out in this election season for its civility, its substance and, perhaps most importantly, its lack of outside spending influencing the campaign.

All of that seems to be fading fast as Brown and Warren swipe at each other with increasing vitriol, and with increasing help from outside sources.

The race's diplomatic tone began to waver at the first debate two weeks ago, when Brown surprised all by beginning with an attack on Warren's claims to Cherokee heritage. The mutual respect had more or less evaporated by last week, when Brown staffers were videotaped at a rally hollering stereotypical "Indian war whoops" and making "tomahawk chop" gestures at Warren supporters.

Last night's debate saw the race turn nastier still, as Brown sustained the attacks on his opponent's character, and Warren painted the senator—known for his independence and bipartisanship in Congress—as an enemy of ordinary Americans and an unquestioning foot soldier of the national Republican leadership.

Brown is aiming for the personal and Warren for the partisan. These two strategies will likely stretch on until Election Day, according to political scientist and Boston College professor David Hopkins.

"The vast majority of undecided voters [in Massachusetts] are Obama voters who haven't made up their mind on the Senate race," Hopkins says. "Brown needs to rule her out as an option for Democrats by attacking her character and stressing his independence."

Warren will appeal to run-of-the-mill Democrats, he said, and make this a choice of her, the popular president and the national Democratic Party over Brown and the national Republican Party.

A further twist in the race is controversy over increased outside spending and Federal Election Commission complaints filed by both campaigns.

Both candidates began this year by signing a "People's Pledge" to curb the negative effects of third-party TV and radio ads. It earned both sides good marks for magnanimity and has so far appeared to keep out the over-the-top negativity and demonization that such third parties usually inject into election season.

However, the pledge does allow mailings and phone calls, and both sides are benefiting from outside spending on the periphery: Groups led by GOP consultant Karl Rove and anti-tax activist Grover Norquist are supporting Brown with robocalls and direct mail, respectively; Warren, meanwhile, has the League of Conservation Voters on her side, and it's running a $300,000 field campaign to get out the vote for her.

These third-party efforts are hardly decisive, but they have spawned a new episode of conflict in the race: Last week, the Massachusetts Democratic Party filed a complaint with the FEC accusing Brown of directly and illegally dealing with Rove on the robocalls. The state's Republican Party responded in kind, charging Warren with commingling with the American Federation of Labor and Congress of Industrial Organizations on mailbox literature, according to CBS Boston.

Some speculate that outside groups will openly break the People's Pledge in the final moments of the campaign. Political consultant Anthony Cignoli told Masslive.com that outside groups may buy up airtime and unleash a torrent of ads over the last 10 days.