(CBS News) With several recent polls showing Democrat Elizabeth Warren with small leads in her Massachusetts Senate bid, Republican incumbent Sen. Scott Brown is out with a new attack ad targeting Warren's character, marking a new negative turn in the closely-watched race.
The ad, entitled "Who Knows?", rehashes claims that Warren improperly identified as Native American in order to further her career. Using a montage of television news clips explaining the controversy - in which it was revealed that Warren in the past listed herself as Native American on some professional forms without documentation proving her heritage - the Brown campaign targets Warren's personal credibility. Featuring a clip from a previous interview, the spot features Warren responding to a question about whether or not there was anything else about her "that's going to come out about you that we don't already know?" "You know, I don't think so, but who knows?" she says, laughing.
With three polls last week showing Warren pulling ahead in the race - although one poll from last week showed Brown in the lead - "Who knows?" is the first of the Massachusetts Senate campaign to go after a candidate on personal terms. The Brown campaign points out that Warren was the first to start airing attack ads, although those ads, "Fighter," and "Too Often," released on September 13 and 18 respectively, go after Brown's record, not his character.
Brown has hammered Warren over the Native American claims for months, but the issue had recently fallen out of the headlines somewhat after months in the spotlight. In a, however, Brown aggressively targeted Warren over the allegations, calling on her to release personnel records from Harvard, where she was a law professor, to prove she did not receive an advantage for being a minority.
"I don't know and neither do the viewers know whether she got ahead as a result of that checking of the box, but the only way that we'll be able to find that out is to have her release her personnel records, have Harvard release their personnel records to make sure that she did not have an advantage that others were entitled to," Brown said last Thursday. "When you are a United States Senator you have to pass a test, and one of character and honesty and truthfulness. And I believe, and others believe, that she has failed that test."
The Brown campaign says the issue matters, and points to last week's Suffolk poll, which had Warren with a 4-point lead over Brown and indicated that "liar" is one of the top words voters associate with Warren's candidacy.
Even as Brown casts himself as a moderate Republican who is willing to work with President Obama, Warren has repeatedly tied him both to Wall Street and to national Republicans, essentially arguing that a vote for Brown is a vote for a GOP takeover of the Senate - and the policies that could result from a Republican majority.
Democrats are, and a Warren victory in Massachusetts could be critical to that effort.
"Sen. Brown is saying, 'I'm going to go to Washington and I'm going to help put the Republicans in control. I think we oughta think about what the implications of that are," Warren told Politico in an interview published Monday.