There's buzz on the Internet over the Rick Perry "was he drunk video". There's an 8 minute version circulating that edited together makes him see really off. This is the full length version, and I'd encourage you to view it before making up your own mind. Nevertheless, the damage may be done. As Jon Stewart said "Best case he drunk, worst case - he's sober."
Is he possibly falling on his sword to rescue the conservatives' last best hope - Herman Cain? Nah. But he' sure helped create a diversion from Cain's 12 year old non-harassment harassment issue.
As for Perry, if he and Cain were to switch spots in the polling and Perry was still the front runner, this would hurt him perhaps in the general election and not the primary. But after Perry's precipitous decline this may just be the final nail in his candidacy. It might not be, but the timing for his campaign is absolutely terrible.