LOWELL, Mass. -- Another Massachusetts Senate debate, another opening question about Elizabeth Warren's native American heritage.

Inside the Tsongas Arena in front of a raucous crowd of over 4,500, NBC "Meet The Press" host David Gregory opened with the contretemps over the ethnic heritage that the Harvard law professor listed in law directories in the 1980s that has consumed much of the attention in one of the nation's most watched Senate races.

Warren calmly explained. Then Sen. Scott Brown shot back, "There's a test you take, and I believe she's failed that test." Gregory then asked about clients of the candidates, who are both lawyers. That set off more charges and counter-charges.

The back-and-forth exchanges, consuming about a third of the debate, show that the contest has gotten increasingly personal. Warren, in a seeming acknowledgement of Brown's personal popularity, has focused on the senator's voting record. Brown has rolled out the native American issue as proof that Warren can't be trusted and has touted his independence from national Republicans.

Brown has tried to distance himself from Republican presidential nominee Mitt Romney, unpopular in Massachusetts, but Gregory tried to pin him down. Brown talked about how bipartisan and independent he is. He finally admitted that he supports Romney, "when it comes to dealing with the economic issues, yes, absolutely." He added that Romney is "out campaigning all over the country. I'm running here in Massachusetts." Brown also praised President Barack Obama.

Warren fumbled a question about which Republican senators she would work with. "Richard Lugar would be one to come to mind," she said, then was quickly corrected by Brown and Gregory, who noted that Lugar lost his party primary. Warren said she was willing to work with Republicans to "revise" Fannie Mae and Freddie Mac, which the government has spent billions to prop up since the housing crisis in 2008.

Brown seized on the blunder to tout his bipartisan credentials, but Gregory pressured him to say whether he would vote for Mitch McConnell as Senate majority leader. McConnell famously said his goal was to make Obama a one-term president.

Brown said he told McConnell that he was "disgusted" with what was happening in Washington. "He's got a lot of work to earn my vote," said Brown.

That answer didn't satisfy Gregory, who ultimately got out Brown to admit he's "undecided" on whom he would vote for.

Warren charged back that Brown was telling Republicans across the country a different story in fundraising pitches that highlight his race as important for the GOP to win Senate control.

Brown started explaining his voting record, which he said that Warren had "misstated," and Warren tried to interrupt. "Excuse me, I'm not a student in your classroom. Please let me respond," snapped Brown to a mixture of boos and applause. It seemed to be a soundbite with lasting power.

The debate moved onto familiar policy territory about taxes and energy, where the candidates have clear differences. Brown wants to extend the Bush-era tax cuts for all earners, while Warren doesn't for the richest. Brown favors continuing oil subsidies; Warren doesn't.

The sharpest policy differences emerged at the end, when they discussed immigration, the war in Afghanistan and the Supreme Court.

Brown said he opposed the Dream Act. "I am in favor of full legal immigration, I don't support it, it's a form of back-door amnesty." He charged that Warren favors drivers licenses for undocumented immigrants (not a federal issue), opposed immigration enforcement and is against "securing our border."

"Senator Brown is right, this is is a big difference between the two of us," said Warren. "I would strongly support the Dream Act."

On the War in Afghanistan, Warren said the troops need to be out now, ahead of Obama's 2014 timeline. "I think that we have always had difficulty with Afghanistan," she said. "We can't stay and rebuild Afghanistan forever." Brown said he supports Obama's timeline, but not the announcement of it.

Brown then said that Scalia was his "model" Supreme Court justice, and the crowd roared. He tried to recover a bit by mentioning four other justices of wildly different ideologies. Warren said her model was Elena Kagan, former dean of Harvard Law.

Brown's Supreme Court gaffe will likely overshadow the candidates' policy differences. After the debate, Warren said she would have liked to talk "even more" about Brown's voting record.

Rep. Barney Frank (D-Mass.) said he was surprised at the opening. "Too little discussion of public policy and too much of a kind of insider politician thing," he said.

Related on HuffPost:

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  • Introduces Financial Product Safety Commission

    Elizabeth Warren <a href="http://www.huffingtonpost.com/2009/03/10/financial-product-safety_n_173691.html" target="_hplink">announced</a> a bill creating a Financial Product Safety Commission with House and Senate Democrats in March 2009. The body was designed to have oversight over mortgages and other financial instruments to protect consumers against predatory practices. She said if the agency had existed before the subprime collapse then "there would have been millions of families who got tangled in predatory mortgages who never would have gotten them." HuffPost's Ryan Grim <a href="http://www.huffingtonpost.com/2009/03/10/financial-product-safety_n_173691.html" target="_hplink">reported</a>: <blockquote>Without all these toxic assets on banks' balance sheets, the institutions wouldn't be on the brink of collapse and the recession would be more manageable. "Consumer financial products were the front end of the destabilization of the American economic system." Sen. Charles Schumer's cosponsorship of the bill is notable because of his proximity to Wall Street. The bill's merit, the New York Democrat said, is that it regulates the actual financial product rather than the company producing it.</blockquote>

  • Geithner Opposes Her Heading CFPB

    Tim Geithner expressed opposition to her nomination for the Consumer Financial Protection Bureau, <a href="http://www.huffingtonpost.com/2010/07/15/tim-geithner-opposes-nomi_n_647691.html" target="_hplink">reported</a> HuffPost's Shahien Nasiripour. Geithner thought Warren's views on the big banks and Wall St. were too tough. Warren's oversight of the Treasury department as a watchdog for TARP apparently irked Geithner, agressively <a href="http://www.youtube.com/watch?v=pz7ruJw6byQ" target="_hplink">questioning him</a> during Congressional hearings: <blockquote>While her grilling of Geithner in September, over what members of Congress have called the "backdoor bailout" of Wall Street through AIG, inspired the "squirm" video, just last month Warren pressed Geithner on the administration's lackluster foreclosure-prevention plan, Making Home Affordable. Criticizing him for Treasury's failure to keep families in their homes, she questioned Treasury's commitment to homeowners.</blockquote>

  • Ready For A Fight

    Elizabeth Warren <a href="http://www.huffingtonpost.com/2010/03/03/fight-for-the-cfpa-is-a-d_n_483707.html" target="_hplink">reiterated her desire</a> for a strong Consumer Financial Protection Agency to HuffPost's Shahien Nasiripour: <blockquote>"My first choice is a strong consumer agency," the Harvard Law professor and federal bailout watchdog said in an interview with the Huffington Post. "My second choice is no agency at all and plenty of blood and teeth left on the floor."</blockquote>

  • Named Interim Chief Of CFPB

    In September of 2010, HuffPost's Ryan Grim <a href="http://www.huffingtonpost.com/2010/09/13/elizabeth-warren-interim-cfpb-chief-consideration_n_715457.html" target="_hplink">reported</a> that Elizabeth Warren was being considered as a candidate for interim director of the Consumer Financial Protection Bureau. Days later the announcement was <a href="http://www.huffingtonpost.com/2010/09/15/white-house-taps-warren_n_715291.html" target="_hplink">official</a>. The move allowed Warren to set up the groundwork for the agency immediately without risking a GOP filibuster of her nomination, a response that seemed certain giving the <a href="http://www.boston.com/news/nation/washington/articles/2010/09/15/opposition_mounts_for_interim_appointment/" target="_hplink">public opposition expressed</a> by some Republican senators. When it came time to put forth an appointment for a longterm CFPB chief, Warren was overlooked, partially because she was seen as unfeasible, but also, HuffPost's Shahien Nasiripour <a href="http://www.huffingtonpost.com/2011/07/18/republican-opposition-to-elizabeth-warren_n_902165.html" target="_hplink">reported</a>, because she was a divisive figure within the Obama administration: <blockquote>Ultimately, Warren wanted the job, allies said. And near-united opposition from Senate Republicans -- 44 of them signed a letter saying they'd oppose any nominee -- should have made it easier for Obama to nominate her, since the Republicans publicly said they wouldn't support anyone for the role. Instead, the Republicans made it easy for the White House to deflect questions about the administration's lack of support for Warren. Asked how she squared the administration's public statements with its private ones, Warren declined. "I really have to say, I'm just not there. I'm not in the intricacies of the political part of this, and I can't comment," Warren said Monday. "The truth is I don't know anything about it."</blockquote>

  • Chats With HuffPost About Bureau

    In October 2010, shortly after being tasked with building the groundwork for the CFPB, Warren stopped by HuffPost to chat with Ryan Grim and Shahien Nasiripour "This is the first real agency we've built in the 21st century -- well, there's Homeland Security, but one for the people. And it means we ought to think differently," said Warren. "The government can talk to people and people can talk to the government differently than when the Consumer Product Safety Commission was built, or when the FDA was built. And if we do this right, that should change the whole dynamic of who this agency really is." HuffPost's Ryan Grim <a href="http://www.huffingtonpost.com/2010/10/07/elizabeth-warren-consumer_1_n_754026.html" target="_hplink">reported</a>: <blockquote>By gathering information, contracts and documents from homeowners and consumers, and allowing watchdog groups and individual concerned citizens access to those documents, the agency can exponentially expand the manpower it has to review the operations of banks and lenders. The goal would be to become aware of a particularly fraudulent practice before it is rampant and insulates itself in the financial services industry.</blockquote> For full video of the interview, click <a href="http://www.huffingtonpost.com/2010/10/07/elizabeth-warren-consumer_1_n_754026.html" target="_hplink">here</a>.

  • GOP Calls Her A Liar

    In May, Warren was called to testify before a House subcommittee and defend the merits of the CFPB. Some of the questions submitted by Republican representatives appeared confused and at times aggressive, leaving Warren to correct them on some basic facts about the actual purpose of the bureau. HuffPost's Mike McCauliff <a href="http://www.huffingtonpost.com/2011/05/24/elizabeth-warren-liar-gop-facts-cfpb_n_866505.html" target="_hplink">relays</a> one particularly contentious moment: <blockquote>The subcommittee chairman, Rep. Patrick McHenry (R-N.C.), began the proceedings by suggesting Warren had lied to the committee in a previous hearing that had questioned the CFPB's role in offering advice to state attorneys general negotiating a settlement with abusive mortgage servicers. At the time, Warren said she was proud her agency had been able to help, at the request of the treasury secretary. But McHenry brought up the memo again, suggesting it showed that she hid a larger role in the negotiations from Congress. "This is our job, and we're trying to do our job, to be helpful to other agencies, and to help those agencies to hold those who break the law accountable," Warren said, repeating that she was proud of the work.</blockquote>

  • Announces Senate Run

    Elizabeth Warren <a href="http://www.huffingtonpost.com/2011/09/13/elizabeth-warren-senate-massachusetts_n_960510.html" target="_hplink">announced</a> on September 14, 2011 that she was running for the United States Senate seat currently held by Scott Brown (R-Mass.) "After listening to people all across our state who know that we can do better, folks who are frustrated like I am that Washington just doesn't get it, I'm running for the Senate so I can fight every day for Massachusetts families," Warren <a href="http://www.huffingtonpost.com/elizabeth-warren/senate-announcement_b_961624.html" target="_hplink">wrote on The Huffington Post</a>.

  • Fundraising

    One month into her campaign to secure the U.S. Senate seat currently held by Scott Brown in Massachusetts, Elizabeth Warren raised $3.15 million, largely <a href="http://www.huffingtonpost.com/2011/10/10/elizabeth-warren-raises-3_n_1003836.html" target="_hplink">from small donations</a>. According to a campaign email, 96 percent of donations were under $100. "These are pretty amazing numbers for our first official finance report, raised in a very short period of time," she said in an email to supporters. Warren's campaign has also attracted <a href="http://www.huffingtonpost.com/2011/10/18/elizabeth-warren-builds-s_n_1018334.html" target="_hplink">large liberal donors</a>, including colleagues from Harvard and well-known liberal donors like George Soros, Barbra Streisand, and DreamWorks CEO Jeffrey Katzenberg. Warren <a href="http://www.huffingtonpost.com/2012/01/11/elizabeth-warren-scott-brown-fundraising_n_1199680.html " target="_hplink">raised</a> an impressive $5.7 million in the fourth quarter of 2011. In early January, the candidate's <a href="http://www.huffingtonpost.com/2012/01/16/elizabeth-warren-money-bomb-fundraising_n_1208511.html?ref=mostpopular" target="_hplink">money bomb</a> pulled in more than $100,000 in just one weekend.

  • Historic Agreement

    Elizabeth Warren and Sen. Scott Brown (R-Mass.) <a href="http://www.huffingtonpost.com/2012/01/23/elizabeth-warren-scott-brown-attack-ads_n_1223574.html" target="_hplink">signed a pledge</a> to curb third-party attack ads. If either campaign breaks the agreement, they would donate half the cost of the outside ad to a charity of their opponent's choice. "This may not work," <a href="http://www.politico.com/blogs/david-catanese/2012/01/warren-this-may-not-work-112119.html" target="_hplink">Warren said in an email to supporters</a>. "But there's enough at stake to make it worthwhile to try to take back this election."