It is a truism in political coverage that an entire debate performance can be overlooked in lieu of focus on a single moment that observers declare ”defining.” It wasn’t in a debate, but former Vermont governor Howard Dean’s scream was such a moment. There was “the international test” from Sen. John Kerry (D-Mass.). Poor President Gerald Ford had his Poland moment. And unfortunately for Pawlenty last night, he had his punt-Obamneycare moment.

My own sense is that the “error” came on Sunday when Pawlenty, whose campaign had previously decided not to go negative on Mitt Romney, came up with the term “Obamneycare.” His campaign, no doubt startled, made the best of it, sending out a flurry of e-mails and YouTube videos.

A very smart GOP strategist told me last night, “Sometimes you have to own those errors.” Pawlenty did not, and he instead tried to reel back in his dig. Now the moniker is useless as a jibe against Romney, the image of a irresolute Pawlenty is reinforced, and Romney gains in stature by not getting nicked up.

It’s a bad moment for the Pawlenty team, potentially breaking the momentum gained with core conservatives after his pro-growth speech. But we shouldn’t overplay it either. Pawlenty’s not “finished.” One debate, early on, does not make a race. But Pawlenty needs to decide (as John King would put it): engage or attack? Last night’s debate showed he can’t do both.