Ballsy but I can't see it as good career move unless he intends to go all the way over to the other side, a la David Brock.
When you forsake your friends you lose all. The enemy will never accept you and your friends will never trust you again. Like McCain, there are some out there who would vote for him because he rocks the boat but he can never get the conservatives to vote for him because of his weaseliness(This word is only grammatically correct when refering to John McCain.)