Over 20 years ago a friend said to me, "You really ought to catch this film Roger & Me. It's by a guy called Michael Moore and it's a very funny documentary about the closing of the GM motor works in Flint, Michigan."
This sounded most unlikely to me. Documentaries were rarely funny at the time, and the subject matter didn't seem to lend itself to humour. I went expecting something worthy but probably dull.
How surprised I was. Moore's film was indeed funny, angry, unusual and utterly devastating all at one time.
At a time when the US airwaves seemed to be increasingly taken over by nasty, talentless shock jocks, along came this filmmaker, talking about the plight of the poor, the greed of bosses, the corruption of government and the resistance of workers, and doing so in ways we just weren't familiar with. The film made such an impact on me that I have never forgotten even trivial details about Flint such as that its most famous son was late-1950s pop singer Pat Boone.
I remember thinking at the time that this was a great, but very personal, tale about the destruction of one man's home town, the factory where his father worked and the community he grew up in. This was surely a one-off.
How wrong can you be? Moore has been with us ever since. His films are record-breaking best-selling documentaries and he has won awards at Cannes and an Oscar. His output has remained highly provocative, entertaining and pertinent to his times.
Apparently angrier as the years have passed, his targets have been all the right ones: gun control (Bowling for Columbine), George W Bush and the warmongering neo-cons (Fahrenheit 9/11), the US healthcare system, or lack of it, (Sicko) and many more.
In the process he has become the bête noire of the US right. Huge amounts of time and money have been put aside to discredit him, yet his standing simply grows.
Up until now though, Moore's attacks on the system have tended to be this or that flaw in it. His latest movie, Capitalism: A Love Story, is surely his most ambitious yet. He takes on the whole system, and does so in the usual humorous, entertaining and yet devastating manner. Even for a seasoned anti-capitalist like myself there were moments that left me truly speechless - for instance, the tale of the privatised juvenile detention centre and the corrupt judges just beggared belief, as did the insurance scam that allows businesses to make millions in profit from the deaths of their workers.
Moore paints a picture of the colossal growth in disparity between rich and poor, the destruction of lives, livelihoods, homesteads and the dignity of ordinary working people. He does so with historical flashbacks, visits to occupying factory workers and activists resisting home repossessions. This is a film of anger, but also of resistance and hope.
Has Moore finally crossed the line into revolutionary socialism? It would be lovely to say he has, but Moore remains firmly rooted in the traditions of US radicalism.
It is an honourable, but flawed, tradition. It takes as its starting point the radicalism of the American Revolution, the founding fathers, the Constitution, the Bill of Rights.
It is a tradition that constantly seeks to show that the right has distorted the dreams of the revolution and betrayed the founding fathers. It is a sentiment that can be heard in the songs of Woody Guthrie and Bruce Springsteen, the speeches of Ralph Nader and the writings of John Steinbeck.
It is most clearly, and perhaps sadly, articulated in Moore's film when he harks back to Franklin D Roosevelt and the New Deal. Moore does not believe everything was right about the US he grew up in (he is acutely aware of the plight of blacks and the Vietnam War), but he does believe things only got truly rotten with the arrival of the man he sees as the corporations' puppet, Ronald Reagan.
Thus like most US radicals he ends up being completely torn by the question of the Democrats. When Al Gore stood against George W Bush in 2000, Moore supported Nader as an independent for president. Four years later he publicly begged him not to stand against John Kerry. In this film he tends to skate over the Clinton administration and sees in the election of Barack Obama the rejection by the populace of corporate America. Unsurprisingly therefore he was hugely enthusiastic at Obama's election, yet you sense the radical's unease as to where it may all end.
Therefore his solutions to capitalism are essentially electoral ones, backed by struggle and popular resistance. This leaves a big gulf between him and revolutionary socialism. But, for all that, he is one of the good guys. We who stand in the revolutionary tradition are all the better for having him and his films as weapons against all that's rotten in the world.