The difference is that to a much greater degree, political writers are participants in the race they’re covering—one way they might “have a great story to cover” is to do what they can “to keep the story going.” The analogy’s not perfect, but it’s sort of like having an umpire with an incentive to keep the underdog close.

Not every political correspondent has been so willing to acknowledge that the press corps has this bias. When, in a recent podcast, Slate editor David Plotz said that political reporters entertain “Rube Goldberg fantasies” about how long-shot candidates still have a chance because “they want there to be something interesting in the spring,” his colleague John Dickerson called the claim “wrong” and “offensive,” and said campaign reporters were—sticking to that sports metaphor—calling the plays as they came, not cheering them along.

But there’s at least some evidence to the contrary. Heilemann cites an analysis from the Center for Media and Public Affairs, which found that Romney received “markedly more negative” coverage “in the ten days leading up to the New Hampshire primary, when the post-Iowa sense of Romney’s inevitability kicked in.”

And anecdotally, while in Iowa I was struck by how readily the media latched onto the story of the “Santorum surge,” which was declared when that underdog candidate was polling in third place. (In that case, at least, the storyline was vindicated—though it’s hard to know how Santorum would have fared in Iowa without the media’s eager attention.)

Or consider this headline from the Los Angeles Times, which practically pleads with readers not to lose interest after Romney’s resounding Florida victory: “Mitt Romney’s Florida win won’t seal race: Despite his landslide victory, the battle for enough delegates to secure the Republican presidential nomination could run for weeks or months.”

(Politico, typically, covers every angle here: a media piece noting the press’s need for drama, a straight news piece that hammers home Romney’s inevitable win, and an analysis piece that argues that the next month is “uncharted territory” and “conservatives are still resisting Romney.” Even Mitt Romney’s inevitability, it seems, flip-flops. Update: Also, this.)

When CJR contributor Brendan Nyhan grappled with this subject after Iowa, he urged reporters to recognize their role in creating campaign “momentum.” Similarly, during the Santorum surge, I argued that the press should exercise “some self-awareness and restraint.”

If Milbank, Heilemann, Lizza et al are any indication, we have plenty of recognition and self-awareness in the press. Now how about that restraint?

Erika Fry is a former assistant editor at CJR.