Some people who like Mr. Cain say he hasn’t prepared well for the moment. “They have not followed the cardinal rule of Crisis Management 101,” said Steve Caldiera, who worked on communications for Mr. Cain at the restaurant association and considers himself a friend. “Above all, you get everything out there right away. They haven’t done that.”…

Cain campaign insiders, including some who have left for other jobs, describe an operation that has ignored many of the basics of a traditional campaign. Mr. Cain dismissed the need for the sort of strategy sessions and daily conference calls that are routine in nearly all full-scale presidential campaigns.

Nor did the former corporate executive ever call for a full internal vetting of his past, current and former Cain campaign aides say. Just as presidential campaigns conduct research on their competitors, most also take steps in advance to fend off foreseeable crises.

That didn’t happen within the Cain campaign. “There was no advance scrub,” said one former Cain campaign aide. “The thought was, ‘Why prepare when there’s nothing there?'”