GOP presidential candidate Rick Perry’s memory lapse at Wednesday night’s CNBC debate will go down as one of the worst debate flubs in history, but it may not mean the campaign kiss of death that the Twitterverse quickly proclaimed it to be.

Despite the national audience of televised debates, a solitary sound bite is rarely the deciding factor between winning the nomination and foundering  into failure.

A 43-second clip that exemplifies one of the candidate’s biggest weaknesses, however, could deal a deathly blow to an already struggling campaign, said long-time political consultant Phil Noble

“I don’t think this in and of itself is going to kill him, but I think that it could become the symbol of what kills him,” Noble said. “If he continues to reinforce this message of not being ready, of not being bright enough or smart enough, then this becomes the symbol of that larger message.”

Perry, who surged to the top of the polls shortly after announcing his campaign in August, has seen his support wane since the beginning of October. Despite his notoriously poor performances in the past six debates, his poll numbers did not dip directly following those less-than-stellar showings.

After the Texas governor’s debut performance -  which became a Saturday Night Live spoof that showed him falling asleep at the podium – Perry’s support increased by 4 percent.

Steven Jarding, a Harvard public policy professor and Democratic campaign strategist, said there were only a few debates in history in which  a candidate has performed so well or so terribly that they made a significant impact on the course of the campaign.

“We can probably name on one hand the five debates out of … 500 that have taken place since the 1960s that really made a difference,” Jarding said. “You can lose it in a night, but it’s hard to win it in a night.”

Gary Langer, the president of Langer Research Associated and ABC News pollster, said Perry’s drop in the polls may have less to do with these on-stage stumbles than with the substance of his policies.

“I think that [his supporters'] departure from Perry has more to do with what they’ve learned about Perry in his policy issues than in how smooth a talker he is,” Langer said. “A slipup in a debate can inform a judgement, but I ultimately expect it to be far less of an influence than the substance of a candidate’s platform.”

It was not until two debates into his campaign that  Perry’s support began to wane. He gained four points following his first debate and maintained that support  following his second debate.

As he approached his campaign’s two-month mark, Perry’s support slumped. In an Oct. 2 ABC News/Washington Post poll released shortly after Perry’s third debate — a Fox-Google contest in Florida – Perry posted half the support of  the previous poll.

And as Perry fell, Herman Cain surged. A USA Today/Gallup poll released in the week leading up to the Sept. 22 Fox News/Google debate in Florida showed Cain tied for fourth place, with   5 percent support.

But in the week following that debate, Cain nearly tripled his poll numbers, tying with Perry for the second-place slot, with 14 percent in .

That was before four women came forward to accuse the former CEO of the National Restaurant Association of sexual harassment .  Polling-wise, Cain’s numbers have not dropped since the accusations were made two weeks ago.

He is still leading in all of the latest polls, but, as Langer points out, Cain’s upward trajectory has flattened. Instead of continuing to climb, Cain now stands at about 27 percent support in a Quinnipiac Poll released Monday. That puts him 6 percentage points higher than Romney, but is less than the 32 percent support he showed in the middle of October.

Unfortunately for Cain, the sexual harassment charges have staying power and continue to produce headlines week after week. Perry’s debate gaffe, on the other hand, is more of a one-day story, Langer said.

“The sexual harassment charges against Cain, while a less-compelling one-time event, have the negative aspect of an ongoing debate and discussion and that can be potentially more damaging,” he said. “If they continue to be evaluated and discussed, they may be potentially more damaging than a flub.”