Bradbury claims his grumpiness has nothing to do with Moore's politics, but the Salon interview linked by Boing Boing contains the following quote:
[Q:] What do you think of President Bush?
[A:] He's wonderful. We needed him. Clinton is a shithead and we're glad to be rid of him. And I'm not talking about his sexual exploits. I think we have a chance to do something about education, very important. We should have done it years ago. It doesn't matter who does it -- Democrats or Republicans -- but it's long overdue. Our education system is a monstrosity. We need to go back and rebuild kindergarten and first grade and teach reading and writing to everybody, all colors, and then the whole structure of our education will change because people will know how to read and write.
Suuure, Ray, I'm sure your fury has nothing to do with your politics. To be fair, Bradbury said the above before Bush demonstrated exactly how incredibly bad he would be. But, in my experience, only people who were predisposed to conservative political views ever trusted Bush at the beginning of his term.
Bradbury is one of the great old men of science fiction. It's unfortunate, though unsurprising, that, like old men everywhere, he's simultaneously turned reactionary and lost touch completely with the zeitgeist.
Let's elaborate on the irony for a moment: Ray Bradbury wrote Fahrenheit 451, the most prominent anti-censorship novel ever written in the English language. "Intellectual property" law is the chief mechanism by which censorship will be exercised in the twenty-first century. In the year 2004, Ray Bradbury is making a ridiculous claim about intellectual property infringement by a film, most likely because the film expresses political views that differ from his own. The Clash never sounded so relevant.
To Bradbury's credit, he's not pursuing legal redress, or seeking to suppress distribution of the film. But nevertheless, by denouncing Moore for borrowing in exactly the way that artists have done in every place and time in human history, Bradbury has pulled a major asshole move.