The king is dead – long live democracy. With the immolation of the News of the World last week, we saw the end of the pre-eminent political influence of the last three decades in Britain. Rupert Murdoch's pass to Number 10 has been withdrawn; the access code for his editors and senior executives has expired. All the unseen deal-making, fixing, manipulation and bullying, as well as that princely sense of entitlement emanating from News International headquarters at Wapping, have gone.

These are very big gains from the events ignited by the revelation that Milly Dowler's phone messages were hacked and deleted by the private inquiry agents working for the News of the World, as she lay dead [see footnote]. Faced with that singularly disgusting act, the nation drew a line: this is not who we are; we won't support those responsible by buying their product; nor will we advertise in that newspaper or tolerate those who do.

It was a lightning revolt with a whiff of the Arab Spring about it, in that the anger was directed at the power of an elderly dynast and his closest associates. There is a feeling of liberation at the end of this highly charged week and we can say that our society seems better off: our political system is freer and, I would suggest, a little bit cleaner; relations between the media, politicians and the public have changed for the good.

The door has shut on Murdoch. Party leaders and backbenchers, from Nicholas Soames to Alan Johnson, won't have him back.

Things do revert in politics but there will never be a return to normal service for the Murdoch family, which has lectured us over the years about standards and trust but whose employees may be guilty of thousands of criminal acts, now accused of suborning and bribing the police and suspected of a serious obstruction of justice with the alleged deletion of email archives.

It doesn't get much worse than this, but think of the eye-watering hypocrisy that occurred in September 2009. Just as James Murdoch was signing huge cheques to silence people whose phones had been hacked, he attacked the BBC at the Edinburgh TV festival with a speech entitled "The Absence of Trust" in which he claimed: "The only reliable, durable and perpetual guarantor of independence is profit."

Nothing better describes the lowering, simple-minded greed of News Corp's heir – values which he has taken from his father. That whole ethic seems suddenly unendurable because we see that they are only in it for themselves and they don't mind who they crush on their way to dominance, whether it is an actress who has had the courage to fight for privacy or the greatest public service broadcaster in the world.

One encouraging part of this enormous story is that it all came from journalists applying exhaustive scrutiny, added by courageous lawyers, in a newspaper that has none of the commercial or political power of the Murdoch press. That is the true independence that plurality, not simply profit, guarantees. Against the odds, Nick Davies and the Guardian team he led prevailed. We should be proud of that, because it shows that there are still organisations that can produce the right result and that we have the type of society that can respond with a clear assertion of values when that result is so obviously shocking.

The revelations are deeply troubling – more so than the MPs' expenses scandal – because the corruptibility of journalists and senior police officers, as well politicians, is laid bare. In the last three years, nearly every part of the establishment has been exposed in one way or another. We are arguably a more transparent society than we were, but it is now much more difficult to believe in our democracy. A free society requires measures of optimism and of faith and what I find hateful about the phone hacking scandal, apart from contempt for people's privacy, is that it further infects British society with cynicism.

David Cameron grasped the magnitude of what was going on last week just in time, though well after Ed Miliband. But the plain fact is that the penny dropped too late for both parties, despite all the evidence made available in the last two years. Both succumbed to the confidence trick that they couldn't win an election without Murdoch's help, nor run the country without giving him the keys to the back door. George Osborne pressed Andy Coulson on the Conservatives, in the hope that he would bring News International with him, while Alastair Campbell and Peter Mandelson arranged for Tony Blair and Murdoch to kiss hands in Australia.

It was galling last week to listen to the likes of Lord Falconer, Tessa Jowell and Alastair Campbell pronounce on the shortcomings of the press without for one moment acknowledging New Labour's part in the creation of the incubus that was Murdoch's power. We do indeed need a new body to regulate the press, as they argue, and new laws concerning the concentration of ownership, but let's not forget that a journalist, not Lord Falconer or Alastair Campbell, was responsible for exposing the scandal.

This story is about the failure of the entire political class. Journalists and politicians, advisers, PR people, writers and lawyers drank Murdoch's champagne, swooned in his company, took his calls and allowed Rebekah Brooks to irradiate them with her crooked little smile. Over more than three decades, the perversion of politics by and for Murdoch became institutionalised, a part of the landscape that no one dared question.

Serious crimes were committed and the police covered them up. Corrupt, or at least badly compromised, relationships became the norm and all but a very few politicians looked the other way, telling themselves this was how things were and always would be.

Other media players had influence, but with the Murdoch group, the relationship with politicians carried over into Gloucestershire weekends, where David and Samantha and Rebekah and Charlie (Brooks, her husband) and Matthew (Freud) and Elisabeth (Murdoch ) – and sometimes Andy, Rupert and James (with or without wives) – wined and dined and rode and walked in each other's company. This embedding of Brooks and Coulson is now the biggest problem for Cameron who, during his emergency press conference, did not even approach an adequate explanation of why he employed Coulson as communications director. Coulson may have misled him on the payments to the police and the extent of phone hacking under his and Rebekah Brooks's editorships, but that is no excuse.

The evidence of criminality was in the Guardian, and in these pages we tirelessly questioned the failure of the police and CPS to pursue criminality, as well as doubting the credentials of Coulson, Brooks and Murdoch to be Cameron's friends. The prime minister was repeatedly warned and, out of fear or infatuation, ignored what we were saying.

This lassitude is striking because up until last Monday morning the government was preparing to wave through the takeover of BSkyB. That is simply no longer acceptable. News International is not fit to own 39% of BSkyB, let alone the remaining 61%. And it seems a bit late for David Cameron to insist on the propriety of the quasi-judicial role of his culture secretary, Jeremy Hunt, when his own office has been so thoroughly compromised by relations with News International.

It is now time for HMG to go after Murdoch and perhaps this is the moment to investigate the complex web of tax havens and offshore accounts that News International has used to avoid paying full tax in the past. I'd bet a month's salary that while NI papers have been urging austerity measures on the UK, the company has used every trick in the book to avoid its proper tax burden.

We're now in a new world, where advertisers and consumers and Mumsnet can exact a terrible revenge on an organisation. Murdoch seems obsolescent and, like the dictators of North Africa, his troubles come from the abuse of power. News of the World journalists ordered the hacking of as many as 4,000 people including grieving relatives of soldiers and of terror and murder victims because they thought their paper was untouchable. The cover-up was further evidence of this arrogance and included misleading Parliament and the Press Complaints Commission, the claimed bribery of the police, the intimidation of legitimate claimants and, it is now suggested, the destruction of digital files in Wapping. Little wonder that last year I wrote here that Murdoch, his children and clannish associates were beginning to match the profile of your average crime family.

Murdoch's troubles will not stop at the UK border. There are questions about corporate governance, which extend to the parent company, News Corp.

Murdoch is 80 and, given James's role in silencing witnesses with hundreds of thousands in out-of-court settlements without his bothering to learn the details, his position as a natural successor must be in question. News Corp's share price has fallen, wiping hundreds of millions off the company's value, and investors surely wonder who is going to retrieve the situation, to say nothing about the continued presence of Rebekah Brooks on the payroll. News Corp is the only company in the west that would tolerate her after what has passed. Perhaps in these final days she serves as lightning conductor for James, a bulwark to further damaging revelations.

Or is it that Murdoch has simply lost his way? Shareholders will urgently want to know what is happening.

To be honest, I couldn't care less about News Corp. It has had its day. The company can be broken up without me losing much sleep. What we should take from these events is a determination never to let a man like Rupert Murdoch hold such sway in our country again. The various inquiries will reveal the true extent of police and media corruption, but we will gain nothing as a society if we don't grasp that Murdoch was our combined responsibility. He saved newspapers and brought us Sky but politicians and public opinion ignored his opportunism and the corrosive effects of his personality. Murdoch and his values are no longer who we are.

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• The following was published on 12 December 2011 in the corrections and clarifications column: An article about the investigation into the abduction and death of Milly Dowler (News of the World hacked Milly Dowler's phone during police hunt, 5 July, page 1) stated that voicemail "messages were deleted by [NoW] journalists in the first few days after Milly's disappearance in order to free up space for more messages. As a result friends and relatives of Milly concluded wrongly that she might still be alive." Since this story was published new evidence – as reported in the Guardian of 10 December – has led the Metropolitan police to believe that this was unlikely to have been correct and that while the News of the World hacked Milly Dowler's phone the newspaper is unlikely to have been responsible for the deletion of a set of voicemails from the phone that caused her parents to have false hopes that she was alive, according to a Metropolitan police statement made to the Leveson inquiry on 12 December.