I guess it really doesn't matter. People's minds are already made up on Moore. For people who believe his BS, no amount of showing them the facts behind his lies/misrepresentations will change their mind (believe me, I've tried), and people who know he's a propagandist would also see his "challenge" as nothing more than his typical grandstanding.
btw, for some reason, this video makes me think (more than I already did) that Thompson is gonna run.