Obama definitely looks like a user.
He isn't wiry at all. Just thin and weak-looking.
But if he is on coke, he handles it well. Most users I knew kept increasing their usage until there were visible and noticeably signs in their behavior.
While Obama seems like a dolt...he doesn't seem shaky or druggy (except his appearance).
He does tend to look at himself often in the mirror...
(perhaps checking for tell-tale dusting on the nostrils?)