McCain is running his own government —
McCain: I’ve Yet to Meet President Trump Since He Took Office
“He doesn’t seem to be that upset that he’s not talking to him,” said German Marshall Fund’s Derek Chollet, a former Obama Pentagon official. “He’s trying to run U.S. defense policy through Mattis and effectively ignore Trump.”
This must be why Mattis has been acting more like a member of the prior administration with his poor choices.