Scott Brown looks like a politician, will Doherty?

Massachusetts Senator Scott Brown was a bit off in his debate with Democratic challenger Elizabeth Warren last night. My colleague at the Boston Phoenix, David Bernstein, suggests that perhaps he was under the weather. And there may be something to that.

But even if he was a touch ill, I think he was in the grips of another, bigger problem.

Two years ago, when Brown shocked the world by seizing the late Ted Kennedy's seat in a special election, he was the truck-driving insurgent. And as I've written elsewhere, he's done a pretty remarkable job of keeping up the everyman image.

Until last night, even the campaign-trail Scott Brown had effectively harkened back to the heady days of 2010: in his ads, he drives around in his truck, visiting veterans and fishermen and all but bleating out "I'm one of you."

But last night, when he stepped into the arena with Warren for an hour and was forced to talk policy he looked like, well, a politician. And even worse for a Massachusetts pol, a Republican.

The final weeks of a conventional race - as opposed to Brown's insurgent, out-of-nowhere campaign in 2010 - have a way of focusing attention on the issues, making the partisan lines a bit clearer.

And that seems to be happening in deep-blue Rhode Island, too, where embattled Democratic Congressman David Cicilline - who trailed Republican challenger Brendan Doherty by 15 points in a February poll - appears to be building a lead on his opponent.

Doherty has made a conscious effort to emulate Brown. But he doesn't have the element of surprise that Brown claimed in 2010. We've known, for some time, that Cicilline was vulnerable. Doherty can't ride the same sudden, unstoppable, issue-obscuring surge that swept Brown into office two years ago. And as the 2012 election cycle builds to a peak - as the partisan divide grows clearer - Doherty risks becoming what Brown looked like last night: another Republican politician.

He can still avoid it; he's not saddled with a voting record, like Brown. If he hits Cicilline hard enough for misleading voters about the state of Providence's finances in the 2010 race - and projects himself as the truthtelling state trooper - he might still disarm the power of partisanship. But it's going to be tough.