When the Plaid Cymru MP Adam Price began his campaign for the impeachment of Tony Blair for "high crimes and misdemeanours" over Iraq, little more than two years ago, Downing Street dismissed him as a crank. His attempt to provoke discussion of his proposal in the Commons was derided as a stunt and blocked not just by Labour, but by the two main opposition parties, whose leaderships refused to sign.
When the Honourable Member for Carmarthen East and Dinefwr produced a report laying out the grounds for impeachment, few gave it credence. One exception, typically, was the then father of the House, Tam Dalyell, who said: "I think as a document it requires refutation in some detail. What they have produced is a perfectly serious document that makes a coherent case." Dalyell warned ministers of the dangers of "dismissing it as a joke", but they didn't listen.
Undeterred by his initial setback, Price changed tack and tabled a motion calling for a committee of seven senior MPs to conduct an inquiry into the events leading up to the war and the aftermath of the conflict. It was this motion that finally led to the debate of 31 October, which Blair had spent three years trying to avoid.
That the government came within 25 votes of defeat is a tribute to Price's tenacity. Anyone watching in the chamber on that afternoon would have to agree that his sober and moving speech was that of a fine parliamentarian, not a crank. His analysis of "government by cabal" provided a telling autopsy of Blair's moribund case for war. The debate also allowed Price to make the case for parliament, cabinet and an independent civil service to act as "a check on hubris in government".
The impeachment campaign was never the joke the government wished it to be: despite the defeat of the motion, ministers will now find it increasingly difficult to avoid a full investigation, even if we have to wait until British troops pull out of Iraq. The Defence Secretary, Des Browne, appears to believe an inquiry is necessary even if the messages coming from his cabinet colleagues are more opaque.
The shameful absence of Blair and Gordon Brown from the chamber shows a residual arrogance at the highest level. But they can ill afford to ignore the clear warning that comes from such a close vote.
As Price rose to speak, I couldn't help noticing that the man sitting two places away from him on the Nationalist benches giving him his full-voiced support was Angus MacNeil, the SNP member for Na h-Eileanan An Iar, who first brought the so-called "cash for honours" scandal to the attention of the police. The government's reaction when it was suggested that some of the Labour Party's fundraising activities could be criminal followed a similar pattern: scorn and ridicule, followed by embarrassment and humiliation.
Blair's twin shame of Iraq and cash for honours will be for ever intertwined when the political history of this decade is written. On the one hand, a foreign-policy catastrophe; on the other, a classic domestic sleaze scandal. But they both resulted from Blair's style of leadership, the so-called sofa government, which allowed him to circumvent the usual checks and balances of democracy. The two crises may seem unconnected, but the sofa remains the same, in some cases down to the individuals in the Prime Minister's inner circle sitting on it - his chief of staff, Jonathan Powell, for example, who is a central character in both stories.
The problem for the Conservatives is that they are deeply associated with both scandals. Because they supported the war and are themselves under investigation by Scotland Yard over funding, they are in no position to take the moral high ground.
The Liberal Democrats, though they opposed the war, have had their own problems with loans from rich backers and have yet to recover from their leadership crisis. As a result, in this parliament, Price and MacNeil have done more to hold this government to account than both the Tories and Lib Dems.
It is the great irony of the situation that if Plaid Cymru and the SNP ever gained their dreamed-of independence, these two great champions of parliamentary democracy would not be sitting in the House of Commons at all.
But it is perhaps fitting that two parties on the fringes of British politics, geographically and ideologically, should have played such an important role in the humbling of Tony Blair. The big-tent politics of new Labour was always designed to homogenise public opinion around one man's electoral project, rather than genuinely allow a thousand flowers to bloom.
In the end, however, the Prime Minister's failure to acknowledge any world-view other than his own has proved to be his downfall. By concentrating power in Downing Street, he really has no one to blame but himself.