Let’s be clear about what constitutes bias.

There are those journalists who pick sides from birth and never change, whatever the circumstances. For reasons of temperament, heredity or because the Pope tells them, they remain rusted on to one side or the other: their party, right or wrong. Few of them end up in the Canberra press gallery itself, but a depressing number find a niche as columnists or shock jocks. For the purposes of this argument they can, and should, be disregarded.

Then there are those who come to a particular viewpoint through self-interest. There is nothing intrinsically wrong with this: so do most voters. But, like the politicians themselves, they should be required to declare their partisanship.

However, in my experience in the press gallery (which admittedly ran from 1969 to 1988; things may have changed) a great deal of what was dismissed as bias was actually judgement; a careful and (usually) sober evaluation of the participants, their performances and their policies.

And, let’s face it. the press gallery was and is in a far better position to make such judgements than the city-based columnists who deride them. In my day and night, gallery journalists were utterly immersed in politics; we lived with the pollies, worked with them, played with them, ate and drank with them and, in some cases, slept with them.

We were in constant contact with their staff members and party apparatchiks. We saw the way their policies developed, which ones were the result of proper research and which were knee-jerk reactions thought up in the bath. We had access to the giants of the permanent public service who could give us historical comparisons as background.

In some ways we were too close to the action, but we were by a long margin those best informed in the country when it came to scoring the two sides. When we distributed our bouquets and brickbats we were generally firm but fair, and always in possession of the facts.

Of course, there were weaknesses: journalists were duchessed and lured into one camp or another, then as now ridiculously susceptible to flattery. But by and large the judgements were pretty sound. Gough Whitlam was, by any rational measure, the supreme politician of his generation, a fact acknowledged even by the Tories. Even John Stone, the Treasury mandarin who later helped to derail John Howard’s 1987 tilt at the Lodge by joining the preposterous Joh Bjelke-Petersen push, voted for Whitlam in 1972 rather than endorse Billy McMahon.

Our preference for Whitlam did not, incidentally, mean that we gave him an easy run; many Whitlamites in the gallery went out of their way give him a taste of the blowtorch. But the judgement was made, and by and large it came through. We praised his vision, his detailed program and his rationalism. And then, when it all went wrong, we were dismayed at his lack of administrative ability and economic nous in dealing with oil-price inflation.

Some time later, one of the senior gallery correspondents made a farewell speech in which he said that he saw the measure of how well he was doing his job by how evenly he was criticised by both sides of politics. I thought this was bullsh-t and said so: there are times when one side is right and the other wrong, and a decision has to be made. Would he have been comfortable being criticised equally in, say, South Africa, then still under apartheid?

He replied that there was no comparison with Australia, which there wasn’t; but the principle still applies. A judgement is not a bias, and for those with the knowledge and authority to make it, doing so is not just a right but a duty. The only proviso is that it should be declared as such.

Far too many gallery journalists pose as impartial, objective commentators while in fact being blatantly one-sided. Increasingly this culture appears to be stifling diversity within individual outlets and even within whole media empires. And yes, of course, I mean Murdoch. You know who you are.