American filmmakers are mad as hell and they're not going to take it anymore. Political parties in this country no longer take opposing the government seriously. But men and women with cameras and film editing skills sure do, and democracy is the better for it.

Famously of course, there's the doyen of agit-prop documentary making, Michael Moore, whose latest anti-Bush tirade, Fahrenheit 9/11 is breaking revenue records for non-fiction films. I use that latter term advisedly.

Fahrenheit 9/11 is definitely not a documentary in the classic sense of the word. It's too polemical, heartfelt and unbalanced. But these are its strengths: Moore's heart and soul are in this naked attempt to convince the American people not to vote for an administration that he says is corrupt, undemocratic and evil.

Moore is spawning many imitators. Among this growing list is Robert Kane Pappas, whose Orwell Rolls In His Grave is a searing treatise on the American media and its corporate ties to big money and the Republican Party.

Pappas, like Moore, doesn't even bother to make the counter-argument, that news costs money and without money there'd be no news. He bares his teeth and goes after Rupert Murdoch, General Electric, Disney and Viacom, the huge corporate owners of huge swathes of American discourse. He tells the chilling story of Clear Channel, which came from a small Texas city in the late 1990s to own more than 1,000 radio stations. All of them play similar music and pander the same rightwing ideology.

Robert Greenwald in his documentary Outfoxed also takes on the media, but confines himself to the dangerous Murdoch-owned network, Fox Broadcasting. News on this network is little more than pro-Bush, pro-Republican propaganda, telling Americans that the greatest threat to their country comes from diversity, tolerance and social liberalism.

Greenwald talks to current and former employees of the network to paint his picture of an organisation that disregards any notion of staying politically neutral in the country's most important debates.

Opponents get shouted down, ridiculed or ignored. Bill O'Reilly, the top Fox hitman, has applied the treatment to Greenwald's film and Murdoch's corporate clout has ensured it is only distributed by direct mailing.

A few years ago, Greenwald also made Uncovered, which tells the tale of the big lies told by America and Britain to justify their invasion of Iraq.

For my money, it's a real documentary, better than Fahrenheit 9/11 in that category, a dispassionate look where real people in politics, the military and government speak their minds.

American dissent is alive and well. It's just not part of the political system anymore. That's a great loss for politics but an gain for film making. Hand me that remote and pour the beer!