It should, of course, have been a glorious anniversary, a last hurrah for Labour's most successful Prime Minister ever, to be followed by a graceful bowing out after 10 ground-breaking years.
That is no doubt how Tony Blair would have envisaged it, back in those far off days when he still held the electorate in the palm of his hand.
For the record, I believe he always planned to stick at 10, and in that sense, the "coup" last September which ostensibly forced him publicly to name the date was superfluous.
But whenever those plans were first conceived, it's a fair bet they won't have included having his parade rained on by the public in the form of yesterday's dismal set of local election results.
Much has been written in the past week about that glad confident morning in May 1997, and how the glad confidence has slowly dissipated throughout Mr Blair's decade in power.
For me, it was a day that will live long in the memory, not just because it was my first election as The Journal's political editor but because being there gave a sense of watching history in the making.
I was in Downing Street that morning watching those cheering, flag-waving crowds and experiencing at first hand the feeling of hope and expectation that Mr Blair's landslide victory engendered.
The memory of it makes it all the more sad that such evident enthusiasm has now turned to such widespread public cynicism.
As it turned out, yesterday morning's results weren't as bad as all that - or at least, not as bad as Labour had pre-spun them as likely to be.
But on the face of it, for the party to finish on a national share of the vote of 27%, just 1 point ahead of the Lib Dems and 14 points behind the Tories, is a pretty dire outcome by any standard.
If repeated in a general election on a uniform national swing, such a result would give David Cameron a Commons majority of 98.
In the North-East, the Tories would win back the three seats they lost to Labour on May 1, 1997 - Tynemouth, Stockton South, and Middlesbrough South and East Cleveland.
Of course, that phrase "uniform national swing" is a fairly large caveat. The Tories are not yet making the inroads in the North they need and once again failed to win a council seat in Newcastle.
As ministers have not been slow to point out, the disillusionment with Labour has yet to be accompanied by any obvious sense of excitement around the Conservatives.
The Lib Dems are scarcely faring any better. Despite isolated triumphs such as their win in John Prescott's backyard of Hull they appear to be flatlining nationally. The plotters who saw off the well-liked Charles Kennedy believing that Ming Campbell was the answer to all their problems are slowly discovering how very wrong they were. Mr Campbell will at least live to fight another day, but for Mr Blair, though, it is now very nearly over.
Whether or not he also stands down as MP for Sedgefield - and even I can't believe he'd treat his loyal constituents with such contempt - he will finally quit as Labour leader next week.
Can he yet go out on some sort of high? Well, the restoration of devolved government in Northern Ireland is due to take place next Wednesday, and the significance of that is not to be sneezed at.
But the inescapable truth is that Mr Blair should not have remained Prime Minister this long, either for the good of the country, the good of the Labour Party, or for the good of his own historical reputation. As I have written before, he should in all conscience have gone in 2003, after the scandalous death of Dr David Kelly following his "outing" as the source of a critical BBC report.
Whichever government flunkie it was who actually leaked the name, a man died, and under the doctrine of ministerial responsibility, it was Mr Blair who should have been ultimately held accountable.
He could and should have made it a resignation on a point of honour.
"I was not responsible for this, and I deplore the chain of events that led to it, but the buck stops with me," he could have said.
Had he done so, it is at least arguable that he would have departed No 10 with his head held high, and with the respect of the British public still intact.
But of course, it didn't work out that way, and although Mr Blair and Alastair Campbell eventually "won" their war with the BBC, it came only at the expense of a catastrophic loss of public trust.
Early in 2004, he seems to have experienced a momentary realisation that this lost trust could not be regained under his leadership, but the so-called "wobble" passed.
Had Mr Blair gone then, and handed over to Gordon Brown while the latter's own reputation was still sky-high, he could have ensured Labour another three-figure majority in 2005.
Instead, he outstayed his welcome by a further three years, and the electoral consequences of that for his shattered party are now plain to see.
Less than a year ago, a leaked Downing Street memo set out plans for a Prime Ministerial "farewell tour", laughably suggesting that Mr Blair should "go with the crowds wanting more."
I wrote at the time that had he genuinely wanted to do this, the opportunity had long since passed, and so it has proved.
What he is actually doing, having chalked up a meaningless anniversary that suggests his real aim was simply to stay in power for its own sake, is going when the crowds can't wait to see the back of him.
And for that, he has only himself to blame.