Something tells me that Rick Perry won't be trying the "my brother" faux-familiarity with Herman Cain the next time they meet up at a Republican debate. The two candidates are in open conflict over Cain's charge that the sexual harassment allegations swirling around him derive from two or three people in the Perry camp who previously knew about the accusations. The context driving the conflict is clear: Perry and Cain have been fighting over the same slice of the GOP electorate: when Perry's polling numbers cratered, Cain's shot up, in perfect inverse.

The flurry of charges and demands for apologies between the two camps leaves me with one question: why doesn' t this sort of thing happen more often? Political consultants are famously mercenary, jumping from one team to another with the constancy of a left-handeded reliever or utility infielder. Why don't we hear of more instances of consultants picking up damaging information about a candidate they're working for one year and then using it, years later, when they happen to be working in the camp of a candidate in opposition to the former employer? Do they do so often but manage to be discreet about it? Or is there in fact an honor among thieves that generally constrains such behavior?

The irony in this case is that it is only because Perry's campaign was in disarray, with Cain shooting past him, that he opened himself up to Cain's accusation. Perry was planning on relying on the same close-knit team of advisers that had guided him through the past decade-plus in Texas. But with his campaign foundering, he (at his wife's urging) decided two weeks ago that he needed to shake things up and bring in new leadership. Among the new faces on board are those with the past ties to Cain -- Curt Anderson, whom Cain now says he told about one of the sexual harassment allegations in preparation for Cain's 2003-2004 Senate campaign; and Tony Fabrizio, who was also on Cain's 2004 team. Then there's Chris Wilson, a partner in a Republican polling firm who is working for the Super PAC supporting Perry; he went on the record yesterday saying he witnessed one of Cain's harassment incidents when he, Wilson, was working at the National Restaurant Association under Cain, but he says he is not the initial source of Politico's revelations of the harassment cases.

The Perry campaign is likewise denying that the initial leaks came from either of the men now in the campaign's employ. "Herman needs to issue an apology to me. That's what needs to happen," said Anderson. Oh, brother.