Critics, of journalism or anything else, don’t tend to engage in prediction. We tend, in fact, to criticize others for engaging in it—since prediction, in journalism, even when it’s valid, has very little value.

And yet. I’m going to break my own no-prediction rule—momentarily—to express a hope, and drop a hint, about tonight. The McCain campaign, inside and outside and around Wash U’s spin room, will be trying its hardest to frame the stories that emerge from tonight’s debate not around Sarah Palin, but around Joe Biden. (Did he snub her? Did he bully her? Did he act professorial or grandfatherly or crotchety or gaffe-y or whatever?)

It’s understandable that the campaign would do this; they’d be, in fact, somewhat silly not to. If Palin flops, then the story becomes “Palin bombed the debate” (and the sub-stories become “should she drop out as running mate?” and “remember when she couldn’t name another Supreme Court case besides Roe?” and such). If she does well, the story becomes “Palin surpassed the low expectations set by all those flubbed interviews” (and all the sub-stories are “she did so much better than when she couldn’t name another Supreme Court case besides Roe” and the like). Neither narrative suits the McCain campaign’s immediate purposes: moving past a fairly disastrous week and focusing on the future. As such: of course they’ll want to hang tonight’s narrative on Joe Biden.

But, though it goes without saying, it also bears repeating: The media need to resist the spin. For most people who will be tuning in, tonight is a referendum on Sarah Palin’s credibility: her familiarity with the issues, her performance under pressure, her fitness to govern. It’s a chance for Palin to transcend stereotypes and narratives and speak, unfiltered, to the voters. It’s a chance for Joe Biden to do that, as well.

And while coverage of the debate will (and must) be comparative—the entire point of a debate is, after all, to juxtapose the two participants, and to contrast their performances—that coverage must also be, simply, declarative. The question tonight should be not just how did the candidates compare?, but also, and more so, how well did they do?. And how well not just in terms of affirming or transcending their media-based caricatures—the gaffes! the charms! the witty bellicosity!—but in terms of, you know, answering Ifill’s questions. It’s a silly thing to have to suggest, but recent history has shown the need to come out and suggest it all the same: Let’s focus, tonight, on substance as much as subtext.

And let’s do so for the coverage of both candidates. Because tonight is not about Joe Biden. It’s not about Sarah Palin. It’s about both of them—two to tango, and all that—and, more importantly, about how both of them present themselves to each other and to the public. Here’s one more hopeful prediction, before we abandon conjecture for good: that the press, in narrating the debate, will remember that.

Megan Garber is an assistant editor at the Nieman Journalism Lab at Harvard University. She was formerly a CJR staff writer.