I've seen various efforts to argue that this wasn't a bad performance by Romney. Or that settling for a bad performance suggests he's in a strong position. I don't find these arguments credible.
Romney looked pained and rambling through most of the debate. I don't think I've ever seen Romney sweat like that, literally or figuratively. And I think national security politics mainly revolves around demonstrations of strength and coherence. To put a finer point on it, dominance. On that count, Obama won hands down.
I don't expect we'll see a decisive move in the polls. My sense is that everyone is already up out of bleachers and rushing onto the field in this election, on both sides. Not many people are still hanging back -- as many seem to have been prior to the first debate. But strength and clarity wins in national security politics -- not catch phrases but demonstrations and body language. Romney looked weak; Obama looked strong. That'll help him.