Christina Patterson: The day I applauded Alastair Campbell

While politics is flawed, it’s the only process for changing our society we’ve got

It's not often that I find myself agreeing with Alastair Campbell. But I do agree with his verdict on In the Loop. "It is," he said on The Culture Show last week, "like the difference between a really good cartoon and a painting".

Political cartoons are, of course, part of a rich satirical tradition. When they're good (and Dave Brown's cartoons, in these pages, are often very good), they can beat 1,000 words, 1,000 inches of comment, even, capturing, in a single flash, an insight that can illumine your breakfast, maybe illumine your day. But they're designed for a moment that lingers, not a moment that stretches out for a couple of hours.

I don't, as Campbell recently claimed to do, often find myself rolling on the floor in response to comedy (perhaps he should get some kind of seat belt? Or leash?) but I did laugh a lot at The Thick of It, Armando Iannucci's Downing Street-inspired satire on spin. That was pure (well, foul-mouthed, but vital, glittering, brilliant) delight. In the Loop, the film version released next week, just isn't. There are some great lines ("At the end of the war, you've got to have some [soldiers] left, otherwise it looks like you lost") and some scarily truthful touches (the aides who all look like "a nine-year-old child"), but overall it lacks the sizzle and fizz of those original bitesize chunks that left you longing for more.

Mark Kermode, The Culture Show's resident film buff, clearly disagreed. Thrilled with Campbell's predicted lack of a GSOH, he could set about demonstrating the sophistication and range of his own. "I have great sympathy," he said, "for anything that portrays politics as essentially venal and crass, because I think that to a great extent it is." Campbell fought back the four-letter expletives for which he is famous, and even managed to stay in his chair. "It upsets me," he said, relatively calmly, "that someone who seems to be quite an intelligent bloke could think that politics was venal and crass, when I can sit down and explain to you how politics has delivered most of the great things in the world and its history."

And that was when I found myself saying, to a silent sitting-room, like some ancient denizen of the House of Lords, "Hear, hear!" That was when I thought of the many times I've sat with arts-loving, literature-loving, film-loving, educated members of the British public, who've stated, calmly – proudly – that politicians are all corrupt, evil and stupid and that they can't be bothered with politics, can't be bothered, even, to vote.

Certainly, you can argue that Campbell's own attempts to manipulate the media have contributed to this culture of cynicism. At least as keen on testosterone as their acquaintances at Westminster, journalists were never likely to warm to a system of favours and threats, of access bestowed and denied, and the energetic verbal outburst that became known as a bollocking. Coinciding with a general trend to scrutinise and diminish any human being with the hubris to single themselves out for public attention (ie pretty much anyone who does anything other than veg out in front of the telly with a bag of Doritos), the result was disastrous. "Government minister not perfect" became the headline on about half the stories published every day. "Government minister claims expenses to which he is technically entitled, but which sound silly." "Government minister's tubby husband watches soft porn."

It all makes a change from Lily Allen, I suppose, or Amy Winehouse, or Madonna and child. Sometimes it adds to the gaiety of the nation. And if you were really stupid, then perhaps you might take it all literally. You might swallow the line that the red tops (and others) spew forth on a daily basis, that politicians are lazy, self-serving, greedy, venal, cynical, stupid people who just want to boss the rest of us around. And who need taking down a peg or two. And then need to be stripped and flayed.

If you weren't really stupid, however – if, for example, you quite liked reading books other than The Da Vinci Code and watching films other than Confessions of a Shopaholic – you might think that some politicians were sometimes remarkably lacking in common sense, and that certain systems – such as MPs' expenses – should be instantly reformed, and that some politicians might do well to learn a language called English, instead of the peculiar mix of repetition and jargon they appear to speak instead, and that most of them would do well to learn that an apology doesn't usually involve the words "if" and "any", and does usually involve the word "sorry". But you wouldn't necessarily assume that errors, in tone, register or performance, were evidence of mass, universal, irrevocable failure.

And some of the sophistication and eye for nuance that you brought to your appreciation of, say, Martin Amis or Frost/Nixon, you might bring to your consumption of the news and your engagement with politics, and you might just think that while politics is usually flawed, it's the only process for changing the structures of our society that we've got, and that while it might be tempting to dismiss the whole caboodle, it would also be childish.

And you might want to think about Beckett's exhortation to artists, and apply it to politics, too: "Fail better." To fail, you have to try.