In my piece on the home page today, I look at the dynamic between Mitt Romney and Herman Cain, who endorsed Romney in 2008:

According to the RealClearPolitics average of polls, Cain and Romney currently lead the GOP field. In Facebook lingo, the two frontrunners have a “complicated” relationship. Beyond a doubt, Romney and Cain have the most extensive business experience of all the GOP candidates. They also both first ran for Senate and lost, although Romney won the GOP nomination. Romney has occasionally thrown a friendly word toward Cain; Cain, in turn, has more vigorously attacked Rick Perry (including announcing last week that he would not consider being the vice-presidential candidate on a Perry ticket) than he has Romney. Underlying their dynamic is a shared interest in seeing Perry lose support: Cain is directly competing with Perry for the not-Romney candidacy in the primary. From Romney’s perspective, Cain can reduce Perry’s support — and if Cain emerges as the main alternative to him, all the better.
Asked for public comment, neither campaign is effusive. “Governor Romney respects Mr. Cain and thinks real-world economic experience is an essential attribute,” says Romney spokeswoman Andrea Saul. A Cain aide is even more succinct, saying simply, “They get along well.”

Full piece here. GOP12 points out that Romney isn’t the only candidate to be unusually kind toward Cain: Newt Gingrich has also gone out of his way to make nice comments about Cain.