Naw, only Obama can defeat Obama.
He would have to mess up big time, and we have yet to see that happen. Not sure how the foreign policy stuff in Libya and the recent US embassy events will play out to his re-election.
Polls have shown that voters trust him on this more than Romney so far, and it's been in the news a lot less than it was a week or so ago (obviously), though it came up again today because Romney talked about it today in Colorado. Unless things get markedly worse in Libya, which I guess they might but which obviously none of us should
hope for unless we are sociopathic hacks, don't see Romney coming back from the fortress of lack-of-credibility that he built for himself with his initial response.