Every newspaper editor since the days of horsewhips and publish-and-be-damned has claimed to be a servant of the needs and desires of the audience.

At its best, this imperative is what divides journalism from public relations and spin – and for that matter, from most other kinds of communication. All of the various inquiries and textbooks, press council guidelines and codes of ethics come back to the same thing: the first duty of journalism is to the public.

The claim can also be both arrogant and dishonest, used to avoid accountability for editorial judgments about which of the public's many concerns should be amplified. Commercial imperatives might normally be assumed to exercise a rough accountability measure on editors' tendencies to amplify their own prejudices, but not always.

Case study: News Corporation's the Daily Telegraph, Sydney's dominant tabloid and Australia's shrillest newspaper. Over the past few months, repeated front pages have left media watchers wondering who the Telegraph conceives its audience to be.

There was the vehement campaign against Labor in the last federal election. One News Corp insider has told me he expects the Tele lost audience as a result. Many of its readers are traditional Labor voters.

Then, in the past couple of weeks, we have had front pages ridiculing those who are unhappy with the budget – which we know includes a substantial majority of Australians. We also know the budget hits middle Australia and less well-off disproportionately hard, including Tele readers.

Against this apparent evidence of a widening divide between audience and editorial line we might put the continuing campaign against cyclists. It's class war. Inner urban ABC watchers might be assumed to be more likely to cycle to work than Tele-reading commuters cursed with a long commute.

So too the campaign for better infrastructure and services for Sydney's western suburbs – credited by some with helping to get political commitment to Sydney's second airport at Badgerys Creek – although that is surely giving more credit than is due, given that it's been on the cards for almost half a century.

Last October News Corp's group editorial director, Campbell Reid, appealed to the "serving the audience" rubric when describing why the Tele was so shrill. It was all about the character of Sydney, he told a forum organised by the media newsletter Mumbrella.

"Sydney has been described as a loud, hungry and vicious, sometimes aggressive place and therefore you get the Daily Telegraph," he said. Adelaide, on the other hand was "much quieter, more conservative" and that was why the Adelaide Advertiser, also owned by News Corp, had been less strident in campaigning against Labor.

How that translates to Brisbane, where News Corp's Courier-Mail was at least as vehement as the Tele, or to Hobart and Melbourne, where the tabloids were more moderate in tone, Reid did not detail.

News Corp insiders know that it is really the choice of editors that determines tone. The particular culture of News Corp Australia makes editors the most powerful people in the organisation.

Paul Whittaker, the editor of the Daily Telegraph, and Chris Mitchell, his mate and editor-in-chief of the Australian, are the most influential editors in the News Corp Australian pack. Both live in Sydney, and cut their journalistic teeth in Queensland.

Brisbane and Sydney are the cities in Australia where the News Corp culture plays out most strongly. In both cities, editors who did not fit the culture have found their tenures unceremoniously cut short in recent years.

How does this relate to commercial imperatives? Not much, although the general disruption in the industry makes evidence hard to find.

The Daily Telegraph suffered an 11% fall in circulation year-on-year for the audit period that ended shortly before last year's federal election. But it is impossible to draw the conclusion that Labor-voting readers were turning away. The Herald Sun was down almost as much – 10%. The Courier-Mail had a smaller fall of 9% and the supposedly genteel Advertiser 10%.

Meanwhile, Fairfax Media titles sank a bone-crushing 17% for the Sydney Morning Herald, and 16% for the Age – admittedly partly as a result of a deliberate move away from larding the figures with cheap bulk deals and unprofitable sales.

Print circulation is down in double digits more or less across the board, with the industry claiming this is more than compensated by digital uptake.

That's a two-edged sword for the "serving the audience" mantra at News Corp, because the industry's new Enhanced Media Metrics Australia measurement for reporting on the total audience across platforms has repeatedly shown that the best-read newspaper in the country is the liberal and moderately toned Sydney Morning Herald. All these figures should be taken with a bucket of salt. The perfect measure of media reach has yet to be devised.

Photograph: Daily Telegraoh

Another measure of newspaper influence is in political outcomes. In the last federal election, the Daily Telegraph in NSW and the Courier-Mail in Queensland campaigned hard against the Labor government.

These were the newspapers that ran headlines about clowns, and "kick this mob out". The Adelaide Advertiser, the Hobart Mercury and the Herald Sun had their moments, but played it comparatively straight in an atmosphere in which Labor was clearly on the nose with voters.

Yet when polling day came, it became apparent that Labor's defeat was built on a huge swing to the Coalition in Tasmania, and a huge surge of support in Victoria. Voters in NSW and Queensland were less inclined to switch governments.

Doubtless many factors, including the quality of the candidates, came in to play – but there is nothing in these figures to support the idea that News Corp telling voters in NSW and Queensland what to think and how to vote actually worked.

It is, I think, the first time in which a strong News Corp campaign against a sitting government has failed to have any discernible impact whatsoever. If I were Rupert Murdoch, that would worry me.