Clooney also has another character up his sleeve. The smooth, calm, collected, uber-cool, somewhat smug guy he played in Michael Clayton, Good Night and Good Luck and Out of Sight.
Given the two, he needs to retire the goofball, the clown, the keystone cop. Playing it broad diminishes his good looks and puts his acting on par with mediocre college summer stock theater.
Apparently Clooney is a big practical joker in real life and maybe he wants people to know he doesn't take life too seriously. (Nobody should ever doubt this. He wore a bat suit with nipples, for Christ's sake.) He needs to fight the urge and stick to what he does best. The gray-templed, square-jawed reincarnation of Cary Grant. George Clooney needs to be George Clooney, the movie star.
Final note: I realize that O Brother Where Art Thou was well received. Give credit where it's due. The Coen Brothers.
Final note: Clooney directed Clooney in Leatherheads. He can only blame himself for this turkey.