As a parable of fascism and freedom, 'Wicked' so overplays its hand that it seriously dilutes its power to disturb. Much of the impact of Baum's original novel, like that of so many fantasy stories, came from haunting, symbolic figures that readers interpret on their own terms. Though there have been numerous literary analyses of Baum's 'Oz' as a coded case for populism and agrarian reform, the book never feels like a tract. 'Wicked,' on the other hand, wears its political heart as if it were a slogan button. This is true not only of the dialogue, but also of Mr. Schwartz's generically impassioned songs, which have that to-the-barricades sound of the omninously underscored anthems of 'Les Misérables.' Though the talk is festooned with cutely mangled word ('swankified,' 'thrillified,' 'gratitution') that bring to mind the language of Smurfs, there's a rock-hard lecture beneath the preciousness. Mr. Mantello reconciles the gap between form and content only in Ms. Chenoweth's performance.