Why he can't pull a Clarence Thomas:
The story's out and there are other candidates to choose from. Cain might not even get the most lift from angry Republican voters — it's so easy to imagine this issue coming up at Wednesday's debate, and Gingrich taking the opportunity to attack the media, channeling the base in a way that Cain's too implicated to effectively do.
But even Cain would be more viable in a general election than Gingrich. And either would be better for the Tea Party base than Romney, the most electable general election candidate after Huntsman.