LAS VEGAS (AP) -- The Democratic presidential candidates hold another debate tonight, this one in Las Vegas.
It comes just seven weeks before the first votes in the nominating process: the caucuses in Iowa.
Polls show Hillary Clinton comfortably in front nationally, but in a much closer race with rivals Barack Obama and John Edwards in the lead-off states.
After months of mostly cordial sparring, Clinton's opponents have been sharpening their attacks. That in turn has challenged her strategy of mainly ignoring rival Democrats and concentrating her fire on President Bush and the Republicans.
Clinton's aides insist she's been preparing for tonight's forum as she has for the others, but acknowledge that she may have to engage more directly as the campaign gets more aggressive.