Click here to watch "Trouble."

Since Super Tuesday, advertising in the Democratic presidential campaign has followed a similar pattern for each contest: start nice, finish nasty. Three new spots from Hillary Rodham Clinton today -- two largely positive and one that contrasts her economic policies with those of Barack Obama -- could be the first sign that the campaign in North Carolina and Indiana will play out that way as well.

Clinton's more assertive new ad, "Trouble," portrays her as the only candidate who can fix a troubled economy. More specifically, it praises her for proposing a freeze on foreclosures and supporting John McCain's plan to suspend the gas tax temporarily. Not surprisingly, McCain receives no credit for the idea; the ad does, however, make sure to mention Obama's opposition to each measure.

If the distinction between "contrast ads" and "attack ads" has any meaning -- with contrast ads highlighting a policy distinction between the candidates and attack ads focusing more critically and personally on their opponent -- "Trouble" would have to be classified as the former. It eschews the confrontational tone of some of Clinton's closing argument ads in Pennsylvania, doesn't dwell on Obama's position and pointedly maintains its upbeat tone and background music throughout. But it's the first ad from either candidate in North Carolina or Indiana to mention the other by name.

Turning again to poet Maya Angelou, who has already appeared in several radio spots expressing her support for Clinton, the campaign on Monday debuted a 60-second TV ad in North Carolina that features Angelou delivering a panegyric to her preferred candidate. "I have found the person I think would be the best president for the United States," Angelou says, highlighting Clinton's commitment to public health, education and jobs.

Also yesterday, Clinton's camp released a new biographical spot in Indiana in which she reminds viewers that she grew up in nearby Park Ridge, Illinois. (She has previously run ads claiming local roots in Pennsylvania and Arkansas [subscription].) Besides reminding voters of her Midwestern upbringing, the ad reinforces the campaign's larger message that Clinton is the candidate most in touch with working people. As if to assure viewers that the race hasn't taken a turn for the negative, Clinton closes on an optimistic note, promising to fight for those "who never stop believing in the promise of America."