I don't have a problem if Richard Cohen of The Washington Post wants to write off Fahrenheit 9/11 as facile and unserious. But this is just silly:
The case against Bush is too hard and too serious to turn into some sort of joke, as Moore has done. The danger of that is twofold: It can send fence-sitters moving, either out of revulsion or sympathy, the other way, and it leads to an easy and facile dismissal of arguments critical of Bush. During the Vietnam War, it seemed to me that some people supported Richard Nixon not because they thought he was right but because they loathed the war protesters. Beware history repeating itself.
Protest in the late '60s and early '70s was widespread, often highly disruptive, and sometimes violent. Once in a while it rose to the level of terrorism. Beyond that, some protesters cheered on the enemy ("Ho, Ho, Ho Chi Minh, the NLF is gonna win"), expressed overt contempt for the country and the flag, and defied traditional mores of language and personal grooming, which a lot of the people at the time still took very seriously.
By contrast, all Michael Moore has done is make a frigging movie.
Nobody's shot a cop in the midst of a bank robbery meant to fund the Revolution. Nobody's plotting to blow up the ROTC building or dose the water supply with LSD. The worst you can say is that maybe a few half-eaten tubs of popcorn are being left in the aisles.