Deep down I knew, when I turned off Romney-Obama Round One after the first 15 minutes, that I would pay dearly for this dereliction of civic duty. Sure, Obama was taking it on the chin, the carnage was unbearable, they should’ve called the fight virtually from the opening bell. But still, the possibility that the genie of unscripted spontaneity might somehow escape from either vessel and provide a moment of political truth — this, if nothing else, meant you were supposed to keep watching, right? Which brings me to “The Rumble 2012,” last night’s ballyhooed pay-per-view online set-to between Jon Stewart and Bill O’Reilly in a D.C. auditorium. Had I known that for this sin of omission I’d be forced to forgo the pleasures of a crisp, pregnant Saturday night in high-autumnal New York to stare at my laptop in solitude, watching two basic-cable titans spar under the deceptive rubric of entertainment, I would have stuck with it to the bloody end.