Mitt's got him on his heels a bit and pulls off a decent barb, "you move (?) fast, Governor. Faster than you talk, which is saying something."
That's the kind of comeback Mitt needs to stick with when he's jabbed. I liked that he grilled Huck on the raising of taxes until he was reduced to saying, "yeah, I raised them, but education is good. What, you don't like children?"