Matthew Norman: Don't pity Gordon – he supped from the devil's hands

From all the untold thousands of words on which the Murdoch obsessive has gorged, it falls to a dozen to capture the story's true essence. They came from Gordon Brown yesterday when he reflected with a cocktail of cathartic relief, anguished outrage and vengeful righteousness, on the empire's inhumanity in discovering and revealing his baby son's cystic fibrosis for profit. He had no idea he was offering such an elliptical commentary on how it came to this, but self-awareness was never a Gordonian strong point. "There's nothing you can do about it, you're in public life..." said Mr Brown.

And there it is, reduced to 14 syllables spoken without a clue of the inherent paradox within them. So what did he imagine his purpose in public life was, if not to fight poisonous vested interests on behalf of the public? What did he tell himself he was doing all those years if the paramount point of power was to retain it by prostrating himself before power?

Mr Brown wept after Rebekah Brooks rang to warn that her Sun was about to splash with his son's illness. This will sound callous to an almost Murdochian degree about a man who has endured so much misery with real dignity, but shed no tears for him. "Are you so blind that you cannot see?" asked Special AKA in Free Nelson Mandela. Mr Brown, who naturally included his hero Mandela in that auto-satirical tome on political courage, certainly was. Having turned his blind eye to the horror, in fact, he adapted his rampant ambition into the patch that masked the good one.

One might ignore his inviting tabloid editors to his new-born daughter's funeral, because in his grief he may have left it to Damian McBride or one of his other subterranean beauties to second guess his guest-list wishes. But acquiescing in Sarah hosting Brooks at that Chequers pyjama party after she ran the story of Fraser's illness he found "disgusting"? Going to her wedding? Would you have done that? Could anyone unwarped have drunk champagne with Brooks and Murdoch after that?

And still he cannot see his complicity. "This is an issue about the abuse of political power..." he said of Murdoch's news-gathering tactics. Well, duh!, you might say. But oddly enough it isn't, or not as he meant it. At its core, it is an issue of the abuse of political power not by Murdoch, but by Gordon Brown, Tony Blair, David Cameron and every other elected quisling who supped with the devil not with a long spoon but from the devil's own satanic hands. "I came to the conclusion," Mr Brown went on of his urge for a judicial inquiry, "that the evidence was becoming so overwhelming about the underhand tactics of News International to trawl through people's lives, particularly the lives of people who were completely defenceless." Sweet Lord Jesus, isn't the point of a Labour prime minister to defend the defenceless? "I'm genuinely shocked to find that this happened," added the Captain Renault of Kirkcaldy. "If I – with all the protection and defences that a chancellor or prime minister has – can be so vulnerable to unscrupulous and unlawful tactics, what about the ordinary citizen?"

Frankly, it's a struggle to continue parsing this statement, because it feels like bullying a simpleton for being a simpleton. So it's worth recalling that Gordon Brown was the most fearsome juggernaut of a machine politician Britain has ever known – and here he is courting sympathy as the impotent victim whose "senior officials" overruled his request for an inquiry. The senior official to whom he refers, if subconsciously, is the ringer for Davros ("My vision is impaired," as his daleks often croaked, "I cannot see") who flew in on Sunday to smile at the cameras as he squired Mrs Brooks to dinner in Mayfair.

When Mr Brown moved next door in 2007, he spoke of wanting something grander than an inquiry. What he really, really wanted, he claimed for five minutes, presumably before a senior official told him not to be daft, was a written constitution. I hesitate to mount this hobby horse once again, because it bores even me half way to a coma. But it is the only long-term escape route from this fetid quagmire. If David Cameron continues to blind himself to this, Ed Miliband has the opportunistic nous to see the value of demanding one. And if not him, let's hear it from Nick Clegg.

The coalition of geniuses who wrote the US Constitution built in all the devices to yoke and separate power because they understood that politicians, being human, are weak and cowardly; that without the protective framework of an undeniably rigid system of government, good intentions must eventually be subsumed by some form of tyranny. No one sane would romanticise US democracy, which is beset by corruption of its own. Yet what we will see when the Feds come after the Murdoch cabal with the full avenging force of American corporate puritanism, as they will, is an endemic hatred for the corruptive abuse of power stemming directly from that constitution and the culture it instilled.The political leader who identifies our need to develop the same, via a constitution, will dominate politics for years to come.

The fine details are for another day, in the unlikely event that it ever dawns. But one small point among so many larger ones is this: the News International cover-up could not have happened under a constitution that enshrined parliamentary authority, so that witnesses were terrified of misleading a select committee rather than disdainful of its wasting their valuable time.

You cannot cleanse the Augean stables with a watering can, or stop the stench returning with a spray of aerosol. If the modes of preventing this corruption are not formalised, it will recur in a modified form. The root problem has never been Murdoch, who is merely its leading symbol. If it hadn't been him it would have been someone else, and very possibly someone worse.

The core problem is that there is no structure to safeguard the likes of Blair, Brown and Cameron from the cowardice and moral enfeeblement that sent their heads corkscrewing into the sand. If they were so blind that they could not see, it needs spelling out in giant capitals. Never again can a British prime minister convince himself that there is nothing he can do to protect the lives of the public because he is in public life.