He has done so repeatedly.
If by "denounce" you mean to say that he states clearly that he disagrees with the views of Wright. That's pretty much the same language that McCain used.
Current Events » in reply to Note: McCain has denounced Hagee,,,When will Obama denounce?
If by "denounce" you mean to say that he states clearly that he disagrees with the views of Wright. That's pretty much the same language that McCain used.