Hillary Clinton's campaign is redoubling its efforts to force Barack Obama to more debates than the two he has agreed to. The Clinton campaign has released a new ad in Wisconsin, a state it's now trying to make a play for, calling upon Obama to agree to debate there. And this ad really goes for the knees, at Obama's strength. At its climax, the ad suggests, "Maybe he'd prefer to give speeches than have to answer questions." Watch it below.