Denzel Washington offers a powerful performance as a proud, intelligent black man convicted of a crime he didn’t commit in “The Hurricane” (1999). Of course, it’s not surprising, since Washington has been nailing variations of the proud, intelligent black man since “A Soldier’s Story.” It would be fair to say Washington has become something like Gary Cooper, James Stewart or John Wayne in that the characters and the man have merged to form a single icon. Sometimes it can imprison an actor. Washington’s challenge, and ours, is to keep finding fresh nuance, as he did with his boxing champ here.