Les Carpenter with Yahoo! Sports has an excellent article out right now about Colt McCoy's young career in Cleveland.
It is apparently becoming a tradition for Texas quarterbacks to be drafted by teams against the wishes of their head coach. The pattern continues with the head coach acting like a petulant child and taking it out on the quarterback and actively trying to make it difficult for him to succeed.
Fortunately for Colt McCoy, in this case the GM fired the sniveling coach and brought in somebody who will try to help the quarterback succeed. Such an approach is apparently much more novel in the NFL than you would think.
Mangini's behavior makes the success McCoy had in his rookie season all the more impressive.