David Laws performed at least one priceless public service. He has punctured - for good - Liberal Democrat hypocrisy and sanctimony about how they stand for a new improved, cleaner, holier politics. A politics that is not possible, and the promise of which is therefore fundamentally dishonest.
Throughout the fuss over MPs' expenses, Nick Clegg, and Laws himself, adopted a posture of nauseating superiority, skating over uncomfortable details of Sir Menzies Campbell's claims for expensive bits of furniture. There was always something wrong with their opportunistic desire to join in the Lord of the Flies pig-sticking in which the vast majority of basically decent but flawed MPs found their reputations trashed along with the tiny minority of troughers.
Perhaps we can now progress to amore mature politics, in which we do not expect Gandhian standards of self-denial of our MPs, merely a sincere attempt to abide by rules that are clear, open and as simple as possible.
I thought Laws was entitled to stay as Chief Secretary. He broke the rules, but not in a serious way; he admitted his error, apologised and is repaying the money claimed. Let me explain why I think that his offence is not serious.
Had Laws been open about his relationship, he would have been entitled to claim up to the maximum for the cost of James Lundie's London flat, which was more than he did, in fact, claim. Had he not been in a relationship with Lundie, he would have been entitled to claim the rent.
As a rich man, he need not have claimed for it at all; presumably he wanted to support his partner, but did not want to give him money directly. All rather confused, emotionally fraught and foolish, but not a hanging offence.
What is interesting is that David Cameron seems to have come to the same view. He seems to have decided, overnight between Friday and Saturday - during that period of meltdown in which all phones near the decision-making process were going through to voicemail - that Laws could stay. This was not simply on the rights and wrongs of the case, of course.
Laws provided Liberal Democrat cover for Conservative spending cuts, which was what George Osborne, the Chancellor, regarded as the real prize of the coalition deal. Laws also turned out to be good at the job in his own right. His detailing of this year's £6.2bn cuts was a model of clarity and conviction, followed by such an assured performance in the House of Commons that some Conservative MPs were only half-joking when they identified him as the next leader of their own party.
A third factor staying Cameron's hand was the muted reaction of The Sun and the Daily Mail yesterday. The Sun had a small headline on its front page, "Cabinet Lib Dem Is Outed in Row Over Exes", and a sympathetic comment article inside headed, "A private person of principle not greed".
Cameron plainly thought that he could ride out the story, provided that there were no new damaging revelations.
In the end, it was not down to him.
There was no need for an early test of the doctrine of "transparent partnership"set out the other day by Nick Clegg: "Of course the Prime Minister sacks, but he does so in consultation with me."
In the end, it seems that David Laws decided the issue. It was the personal that trumped the political, just as it had been the personal that got him into the mess in the first place. It was, apparently, his mortification at having to out himself that made it impossible for him to carry on.
Politically, of course, it would have been difficult to continue. Difficult, but I would argue that it would have been better if Laws had been required to drop the pretence that he was the seagreen incorruptible of the Lib-Con Revolution. He used to boast that he made "the second lowest claim for London living costs of the 17 MPs for the Somerset and Dorset", which was, in retrospect, a rather suspect statistic.
On Friday, before his Fall, it was reported that he had not only refused a pot plant for his office in the Treasury but had demanded to see the budget for all pot plants in the department - and abolished it.
Yes, after Laws had been outed as a human being, his credibility would have been weakened. Every cut he proposed would have been met by a snide and partisan response from vested interests and Labour MPs, pointing out that he wrongly claimed £40,000 of public money. That would have been a price well worth paying.
Indeed, it is a price that has now been paid, regardless.
It is dangerous for democracy to have people who think that they are Robespierre - and who are glowingly written up as pure of heart and stern of fiscal discipline - operating the guillotine. Now we are back to politics as usual, and that is healthier for us all.From now on, the politicians telling us to tighten our belts will not be doing so from a high moral pedestal.
After all, even George Osborne repaid £1,936 in January this year, which he had unintentionally overclaimed on his mortgage.
That is a good thing. It will help people to avoid falling for the myth that there is a transcendant alternative to real politics that is purer than pure, and then becoming red in the face with pious fury when politicians turn out to be decent but less than perfect. There is nothing more damaging in politics than the curse of high expectations.
I think it is a shame that David Laws felt he should go. Evidently, it would have been possible for him to stay on, and to do the job with the advantage of being free of the weight of unrealistic expectations.
The coalition is going to have to work against a sense of public disappointment at some point. But it seems pointless to have to do so without the evident talents of David Laws. That just makes matters more difficult than they are going to be anyway.
John Rentoul blogs at: www.independent.co.uk/jrentoulReuse content