BY THE TIME the world got to see the videotape of Marion Barry at the Vista Hotel yesterday, the general story line had become fairly well known, and there were no unexpected twists. Still, it was a poignant moment in a special sense that went well beyond whatever legal scoring the opposing lawyers and the jurors may award it. There before all eyes was the mayor of Washington, as played by himself, in a role that most Washingtonians across the wards had not seen for themselves -- and for the most part cannot have genuinely enjoying viewing. Whatever anybody may think about the circumstances that led to this event -- and there is ample room here for misgivings that may have nothing to do with legalities -- the sights and sounds of the Marion Barry in these scenes were not those that any constituent would want to attribute to the mayor of the capital city or the presumed leader of its efforts to rid the neighborhoods of drugs and the violence spawned by the drug trade. There is the mayor who not only denied up and down during the years any personal use of illegal substances, but who sermonized constantly -- and movingly -- on the evils of drug use.

The tape is startling and disturbing even though you knew more or less what it would show. It is not good family viewing. Right there for young and old, for children who live in the middle of the drug markets is this mayor talking about using drugs and lifting a pipeful to his face before authorities move in for the arrest. The arrest scene is not at all pretty, either. Again, leaving aside the unresolved legal implications of it, the reading of his rights, the handcuffing and the bitter string of profanities from the mayor make you want to look the other way. The judgment on all this is yet to come, and the tape may or may not figure heavily in it. But the drama in this footage is heavy enough in itself.