Many presidential campaigns have prolonged periods when they are in a slump and other times when everything seems to go right. These ups and downs aren't usually decisive, but they seem significant at the time. For example, in 2000, Al Gore trailed George W. Bush badly throughout the spring and summer. It wasn't until his VP pick of Joe Lieberman, his triumphant convention and the weeks of campaigning coming out of it that Gore ended up with a slight lead, having trailed by as many as 18 percentage points. There are few endeavors where momentum feeds more on itself than a presidential campaign.

I thought about this as I watched the network news last night, those journalistic relics, now a series of interstitials for one long pharmaceutical ad. There was Mitt Romney in western Ohio saying President Obama is an enemy of coal. And there was Obama in Iowa framed by windmills. Just months ago, when the president was struggling, it might have been tempting to make some quixotic reference about the president's fortunes. But yesterday the imagery, at least for me, suggested that Romney is part of the past; the president the future. Romney wasn't even talking so-called “clean coal”; he was talking about old-fashioned coal, which is losingto cleaner burning fuels. And, to top it off, the networks showed Obama having a little fun with Romney. Obama quoted Romney's dismissal of wind energy, “you can't put a windmill on your car and drive it” and then ribbed him for the famous dog on the roof story.

On last night's news, the president looked like a winner, Romney a bit of a loser and "that's the way it is" when one candidate is streaking and the other slumping. It was just one story from one night, and judging from the commercials, the audience may not make it to November anyway. But last night's snippet underscored the growing importance of Romney's convention. Will he have a conventions that soars like Gore's, or one that crashes like Dole's?