Debate detritus. Shannon O'Brien, what I liked most about you in last night's debate were those shoulder pads. If I were the quarterback and I saw you coming after me, I would ditch that football as fast as I could. And yes, I would love to see your tattoo. Mitt Romney, what I liked most about you was that ghoulish make-up, slathered on two days before Halloween so that you could scare the kids who happened to stumble on you and Shannon instead of SpongeBob SquarePants.

What I liked least about both of you was your mindless insistence on arguing about things that aren't relevant to the public. It's not that I don't like negative campaigning. Quite the contrary -- I love negative campaigning. But it ought to be over what challenges the next governor is facing, not impenetrable accusations about each other's minuscule roles in corporate malfeasance. And even though I share O'Brien's suspicion (to cite one example) that Romney does not, in his heart of hearts, believe in a woman's right to choose, he's laid out such an unambiguous pro-choice stance that it would be impossible for him to back down. As Romney reminded viewers last night, O'Brien hasn't always been pro-choice, either.

If nothing else, last night was a good show. Boston Herald publisher Pat Purcell's decision to bring in celebrity interviewer Tim Russert as the moderator provided to be inspired. As Mark Jurkowitz notes in today's Globe, Russert did a better job of keeping them focused on issues (if not necessarily the issues) than anyone else has been able to manage. Still, I would have preferred a local moderator -- say, someone like David Brudnoy or Christopher Lydon. At one point, Russert repeatedly pressed O'Brien on whether she would ease Proposition 2 1/2 to allow financially pressed cities and towns to raise their property taxes. Trouble was, Russert seemed not to know that they already can, through a local referendum. And Jurkowitz confirms that it wasn't just my imagination: Russert really did pronounce House Speaker Tom Finneran's name as "Finnernan."

Though it would be hard to pick a winner in this debate, I guess I'd have to give it to Romney on style. The guy who couldn't even best the barely coherent Ted Kennedy eight years ago struck upon a fairly effective approach last night, as Joe Battenfeld notes in the Herald. To paraphrase the old lawyer's saw, when he could argue the facts, he argued the facts; when he couldn't argue the facts, he argued politics; and when he couldn't argue politics, he looked mournfully at O'Brien and said, Oh, Shannon, Shannon, Shannon, that's so unbecoming; can't we elevate the tone just a bit? Sure it was disingenuous, but in the final days of a campaign you're trying to win over the undecideds -- the least interested and least knowledgeable members of the voting public. They're going to remember Romney's wounded tone long after they've forgotten what O'Brien claims is on pages seven and 11 of Romney's position papers. O'Brien's been pulling her 7-Eleven stunt for weeks now, and it hasn't worked yet. No surprise there: by her own telling, Romney has proposed taxes to discourage SUV ownership and development that would encroach on open space. All she's succeeded in doing is making Romney look like a better environmentalist than she.

One thing that did work in O'Brien's favor last night was the absence of Green Party candidate Jill Stein, the only one of the three "other" candidates to make much of a favorable impression to date. Stein's presence in two previous debates served mainly to remind liberals how short O'Brien falls of the progressive nirvana they seek. Without Stein, O'Brien was able to posit herself as a far more reliable defender of liberal values than Romney. For all her centrist mush, O'Brien managed to make it clear last night that she would protect us from the dehumanizing evil of capital punishment, and would assent, however reluctantly, to another tax increase before she would dismantle public education or destroy programs on which senior citizens depend. The Globe editorial page, which has already endorsed O'Brien, declares her the winner on points. That's probably about right. The question is how many viewers were keeping score.