What’s this? Michael Moore under investigation for a trip to Cuba? The Treasury Department investigating alleged violations of the Helms-Burton Act? Indignant headlines? Tearful press conferences?

Must mean he’s cranking up the publicity machine for another film. Let’s check.Oh, hey, look at that…”Sicko” is premiering at Cannes this week. Quel surprise.

Michael Moore is a director I know I really should like. I agree with most of the basic ideas that underlie his films. Big corporations frequently DO treat their workers like shit. America’s gun fetish IS out of control. Bush’s war is a bloody fraud and a disaster. And access to health care in the US DOES suck.

And there are other reasons I should like him. He’s frequently very funny, with a wicked sense of theatre. More interestingly, he has pretty much single handedly breathed life into the documentary, a form of film that a decade ago was produced mostly for TV and small art-house audiences. There have always been American masters of the genre - D.A. Pennebaker and Barbara Kopple, for example - but interest in Moore and his work has dragged the documentary from specialty channels to your local twenty screen plexes; his success has launched a whole new wave of documentary film-makers.

But are they?

Traditional documentarians adopted many of the values of traditional journalism - objectivity, non-involvement and non-intervention, and invisibility. Viewers were being presented with unfiltered, truthful, real world moments, a window on reality.

This has always been at least partly bullshit, of course. Virtually all of the seminal documentaries by Robert Flaherty were staged; and every writer, reporter, editor (or, for that matter, intelligent reader) knows that the act of selecting what footage to keep and what to omit is an editorial decision that profoundly changes the nature of the “reality” shown in even the most scrupulously “objective” documentary.

But there’s a fundamental difference between shooting what happens in the real world and editing it to focus viewers on specific aspects of a recorded reality, and staging a new series of events to make an editorial point. It may be entertaining, it may educate, and it may even persuade - but it’s not documentary film-making. Driving an ice cream wagon around the Capital building reading the Patriot Act is good political theatre or performance art; but it’s not documentary film.

Nor would traditional documentarians - the ones I respect, anyway - knowingly lie. Moore does - directly, by omission, and by manipulation.

None of that really matters. If it’s effective, what difference does the label make? Moore’s goals are presumably social, not artistic. He’s a propagandist and an advocate, using his own peculiar form of film as a tool for achieving political ends. If it works, I suppose, all this quibbling is irrelevant. And he IS funny. But I’ve found that with each successive film, the power of his actual arguments has waned while the political theatre and smug mockery have taken over. More and more they feel like a series of loosely linked skits, with a sense of mockery replacing anger. I found the last scene of Bowling for Columbine - the one in which Moore first deceives, then mocks, then berates an aging and confused Charlton Heston - almost unwatchable.

And that’s a shame. Because I want to agree with him. I just won’t watch his films any more.