Barring a disasterous performance, the winner or loser of a presidential debate is almost always decided in the days following, as pundits, reporters, and partisans work to shape a narrative of what happened. And judging from the chatter this morning, Mitt Romney’s losing (but generally solid) performance might — by the end of the week — transform itself into a terrible loss.

His answer on Libya has a lot to do with it. Romney began with a little Republican boilerplate: Asserting that the “buck” stops with the president, hitting the White House for not providing additional security, and hitting Obama for taking his time before condemning the attack as an act of terror.

As has been the case throughout the campaign, Romney’s problem is that this rhetoric lacks a firm foundation in the truth. The day after the attacks in Libya, President Obama gave a short address in the Rose Garden, where he described the events as an “act of terror” and pledged to “hunt down those who committed the crime.” Obama pointed this out during the debate, and was immediately challenged by Romney, who claimed — in short — that Obama was lying: “I want to make sure we get that for the record because it took the president 14 days before he called the attack in Benghazi an act of terror.”

At this point, the moderator, Candy Crowley, stepped in and explained that yes, Obama did describe the attacks the next day as an act of terror. Obama asked Crowley to say this “a little louder,” and the audience responded with clapping, as if to say “Thank you for fact checking Romney.”

It was the mos t brutal moment of the debate. More to the point, though, it was a direct product of Romney’s foreign policy convictions, and his substance-less view that the best way to project American strength is to label things as “terror” at every opportunity. What’s more, it was fed into Obama’s (somewhat self-serving) critique: That Romney was and is too eager to politicize a tragedy.

It’s also been picked up by the news media as the most important exchange of the night. Time‘s Joe Klein called Obama’s answer to the initial question a “stirring response,” and ABC News’ Rick Klein pinpointed the Libya moment as when Obama “hit a stride.”

Likewise, Politico’s Mike Allen called it a “key moment.” Mark Halperin said that Romney’s answer was “the closest thing to a moment, a horribly weak moment, I think that the debate had. The New York Times’s Andrew Rosenthal compared Romney’s response to Gerald Ford’s famous declaration in the 1976 presidential debate that there was no “Soviet domination” of Eastern Europe.

None of this is to say that Romney has irrevocably harmed his campaign with this debate and this moment. But he has ensured a week of bad coverage, and has given ordinary people a moment to chew on and think about as they wait for the next debate. Which, it should be said, will be focused on foreign policy. And given the extent to which Romney doesn’t seem to have a foreign policy vision that goes beyond talking tough, there’s a chance that next week, we’ll see a repeat of last night’s failure.

Jamelle Bouie is a staff writer at The American Prospect , where he writes a blog .