Debate Preview: Cleveland Rocks

Part three of the Clinton vs. Obama debate-a-thon airs tonight (9 p.m., MSNBC), and it’s being billed as the last, final, ultimate one-on-one showdown ever, forever … until Hillary steamrolls Obama in Ohio, and we do it all over again. But the past week has not been kind to Clinton, what with Obama closing the gap in Texas, both sides breaking even in the NAFTA debate, and her “major” foreign-policy speech getting eclipsed by the dress mess . But the debate stage is still her turf, making the drama behind tonight’s face-off slightly less contrived than usual. Here are a few things to look for as you struggle to avoid clicking over to American Idol :

Which Hillary? Clinton has been positively schizophrenic recently, sounding defeated at one moment, angrily brandishing oppo mailers the next, and offering stately disquisitions on foreign affairs for good measure. Which Hillary will we see tonight? If recent history is any indicator, all three! She will probably go easy on the canned lines, however: Last week’s “Xerox” quip bombed, and her policy-based attacks have been more effective, anyway.

The new front-runner. Obama turned in a solid performance at last Thursday’s debate, arguing Hillary to a draw. But a flubbed answer or ill-advised put-down can undo everything. Look for Obama to stick with last week’s formula: shrug off attacks as petty, beat back Clinton’s “experience” case, and insist that inspiration is more important than bullet points.

Negative Nancies. Over the weekend, Hillary held up an Obama mailer attacking her health-care plan and record on NAFTA and challenged him to ” meet me in Ohio .” Well, here they are. In most debates, the candidates leave their harshest words at the door. But this could be Clinton’s last chance to ding Obama for resorting to negative attacks while claiming to represent a new kind of politics. Obama has plenty of ammo in that clip, too, the Wajir photo being the freshest (if not the most incriminating) example.

Trade pandering. Nowhere are the negative effects of NAFTA more palpable than Ohio, where manufacturing jobs have dropped steeply. As a result, Obama and Clinton have spent recent weeks flogging each other over trade, each claiming that the other has said positive things about NAFTA. Both are sort of right , which makes the argument as close to a stalemate as can be—and therefore likely to generate plenty of heat. The Tim Russert Quote Machine will no doubt be in top form. As for Ohio-targeting, Clinton can relax slightly. She retains a lead in Ohio polls, where demographics—more rural whites, fewer urban blacks—skew to her benefit.

Network tensions: When MSNBC’s David Shuster suggested that the Clinton campaign was “pimping out” Chelsea Clinton, the campaign threatened to boycott all future NBC debates. They later reneged (for a campaign that’s pushing for more debates, it doesn’t make sense to skip one), but residual tensions could flare up, especially if they bring up the media’s treatment of the candidates.

Check back at 9 p.m. for a live blog of the debate. And maybe a little American Idol .