In it, but not of it. TPM DC
Carville presumably made the quip at a Christian Science Monitor breakfast where he was speaking this morning. But he's actually made a similar point before.
Speaking to Newsweek back during the 2008 campaign, in an article about Obama's relative political toughness compared to Clinton, Carville said: "If she gave him one of her cojones, they'd both have two."
(Politico also wrote about Memoli's tweet.)