THE new film “Idiocracy” sounds like a sure winner. It was directed by Mike Judge, creator of the animated TV series “Beavis and Butt-head” and “King of the Hill,” and director of the sleeper movie hit “Office Space.” It stars Luke Wilson. It has received good reviews from the few critics who, despite the efforts of 20th Century Fox, have been able to see it.

So why did Fox, after sitting on the movie for two years before releasing it Sept. 1, decide not to market the film, opting instead to open it quietly in only 130 theaters and then quickly send it to video? Judging by the online reaction, there are at least two possible reasons.

The first is that the film is simply too stark a critique of American culture, or even that it is a cautionary tale about low-intelligence dysgenics (essentially, overbreeding among the stupid). The movie depicts a future in which everyone has become so dense and culturally lowbrow that Mr. Wilson’s character — an average guy from the present day who travels by accident hundreds of years forward in time — is a relative genius. Why, asks David Weigel on Reason magazine’s Hit and Run blog (reason.com), do “movies that exploit dumbed-down American culture get wide releases while a comedy making light of that, by the creator of ‘Beavis and Butt-head,’ is getting canned?”

He points to another blogger, Ilkka Kokkarinen, who writes that the implications of the movie’s theme — flatulence jokes aside — “are so immensely serious that it is simply unimaginable that any studio boss would take the slightest chance of becoming the next Mel Gibson over the idea that society of stupid people is worse than a society of smart people.” (sixteenvolts.blogspot.com) Populists — defenders of the little guy — would not stand for it, Mr. Kokkarinen says.