What is Mitt Romney Hiding?

Romney hits Reid for being a "dirty liar" but the GOP nominee won't come clean on his taxes. My new post for Politico. http://www.politico.com/arena/perm/Brad_Bannon_2AFC52B2-0E43-4A7F-81B1-0C83F722A79C.html#.UCATwu32JwA.twitter via @POLITICO