The really depressing thing about British corruption scandals is their size. They're always so small, so petty, so nugatory that it's a wonder we dignify them with them with such fierce attention. They are displacement activities, distracting us from the proper scandal we have preferred to ignore for too long.

Glancing with distaste at the quartet of Labour peers who seemed happy to take a few bob to tinker with obscure legislation, the mind flits across the Atlantic. When Illinois governor Rod Blagojevich felt the urge for self-enrichment, he embraced the project with gumption by deciding to auction off the Senate seat vacated by President Obama for a million bucks and more.

And here? Well, here a bunch of 15th-rate Labour hacks lolloped gleefully into a trap an averagely media sussed 14-year-old would have nimbly sidestepped, just as Neil Hamilton waltzed into the Paris Ritz without wondering if placing his career in Mr Al Fayed's vengeful hands was a spiffing idea. At least dear old Blago has the endearing lunacy to continue insisting he hasn't done a thing wrong. Our nebbishes can't even bluster with style, tending to witter that while they don't believe they've been naughty, they're frightfully sorry if some arcane infraction of 14th-century rules has brought the Muthah of Parliaments into disrepute. As if it was in repute in the first place.

Wretches the lot of them, yes, but wretches deserving no more than a dismissive sneer. Leave them to rot on the red benches, bang 'em up in HMP Ford, grant them grace and favour holiday cottages in Haverfordwest, waterboard them... does anyone honestly give a damn what becomes of them? I don't think so. This is one of those five-day news stories that whoosh over the heads of an electorate already so abundantly fed up with its ruling class that the misadventures of a few nonentities is like a bout of athlete's foot at the end of a gangrenous leg.

The sickness that should worry us is something more threatening than systemic Westminster avarice stretching from selling marginal legislative influence to charging the taxpayer for garden plants and featherbedding pensions. These are minor symptoms of the underlying disease, which is necrotising apathy. They don't care what we think of them, and that's because they think we don't care that they don't care what we think of them. It's a perfect vicious circle of mutual contempt, and to this extent an harmonious marriage of minds between rulers and ruled.

If there was genuine concern for the political process, the issue of the week wouldn't be the claims of trifling corruption among peers, but the colossal corruption of amoral government. Buried in the rubble of the idiot peers yesterday was confirmation from the Information Tribunal – a body with an engagingly Soviet title, but little of the implicit power – that the minutes of Cabinet meetings committing Britain to invade Iraq must be published.

The government will resist for as long as it can, of course, although God knows what it's afraid of when everyone knows all the important decisions were made on sofas in minutes but without minutes. Presumably it's the instinctive phobia of openness that defines politics in a building architecturally designed, with all the hidden nooks and secluded crannies in that neo-Gothic hellhole, to encourage scheming and secrecy.

More and more, the most attractive first step in the fantastical quest to rebuild our politics is the one Guy Fawkes had in mind. Once again I commend to you the vastly underrated movie V For Vendetta in which a latter-day Fawkes succeeds where Guido sadly failed, though I'd better add the ritual disclaimer that I am not inciting anyone to plant gelignite beneath parliament lest a costly police investigation under anti-terrorist law be launched.

Alternatively, David Cameron might consider getting serious about sequestering Obama's message of change. The Tory guv'nor choked on his breakfast porridge, he confided to yesterday's Independent, when he read that Gordon Brown had described the economic crisis as "the birth pangs of a new global order". But what should have him gagging is the prospect of the public handing him power on no more inspiring grounds than distrust of an incumbent administration that has disgraced itself in almost every imaginable way, and sullen fatigue at being condescended to like credulous children.

The lesson from America could not be clearer. Far from being scared of being treated like adults, voters love the idea. When Obama spoke about race back in March, he gave the greatest speech of our lifetimes because he told the simple truth in all its nuanced complexity. Many thought the candour would destroy his candidacy. It saved it, and elevated it to heights unscaled in memory.

Mr Cameron is no Barack H, but he is bright, thoughtful and to some degree bold. He may yet show the capacity to ignore the received verity that counsels against trusting people with harsh realities... in this case, that the entire political system is ruined; that it lacks the checks and balances against executive power, with the growing threat to civil liberties among other menaces, that are the minimum requirements of an effective democracy; that the absences of mechanisms to expel dodgy peers from the Lords and hold Cabinet ministers and prime ministerial advisers accountable for war crimes are but two of countless pernicious by-products stemming from the lack of a written constitution.

Times of great crisis are also times of great opportunity, because only then is the public more terrified of the status quo than of seismic change. It happened in the States under FDR, and will happen again under Obama. If ever there was a moment when the British people, for all our transcendent apathy, were ready to embrace a radical reconstruction of this hideous apology for a democratic system, that moment is upon us now.

We are an ever-atrophying post-imperial power in grave need not of clinging to the façade of global relevance offered by a permanent seat on the Security Council and the renewal of Trident, but of renewal itself; and primed by economic petrifaction and lingering disgust over that war to accept some brutal truths about how we have sunk so low, and how we might begin to rise again.

There are stronger reasons for choking on porridge than a PM's pontifications about the economy.