If the Littleborough and Saddleworth by-election has had one side effect above all others, it has been to propel Peter Benjamin Mandelson into the spotlight once again. So far did he dominate the Labour campaign, with his mixture of whimsy and menace, that it was at times impossible to remember that he was the minder and not the candidate.
But the real significance of the appointment of Mandelson to the by-election job goes beyond the brilliantly successful and heavily criticised campaign that he ran; it marks the most public acknowledgement yet of the trust vested in him by Tony Blair.
It was Blair, rather than Mandelson, who thought the Littleborough and Saddleworth seat was winnable; and it was Blair who was determined that the 42-year-old MP for Hartlepool, grandson of Herbert Morrison, and "anti- Christ" to the old left of the party, should run the campaign.
It is partly that level of trust, of course, which variously exasperates, intimidates and inspires envy in so many of Mandelson's parliamentary colleagues. Which raises the question of how important the "real deputy leader" of the Labour Party, as his denigrators have it, truly is.
He is certainly among the three or four people who speak most with Blair day to day. But that doesn't mean he is at every meeting that matters. Before Prime Minister's Questions, for example, Blair will talk to key members of his private office, a lawyer friend such as Lord Irvine and, according to one intimate, "always to Gordon [Brown], not always to Peter".
What Blair is said to see, above all, in Mandelson - far above the parliamentary party's obsolete obsession with him as a spin doctor - is his intelligence and strategic skills, his hyper-acute antennae, his ability to see a problem a week or a month ahead. Perhaps the best term for Mandelson's role in Blair's life, if it weren't for the Mafia connotations given it by Mario Puzo, would be "counsellor" - a combination of adviser, confidant and discerner both of what is possible and necessary.
He is, as one shadow Cabinet admirer puts it, "exceedingly honest and direct with his colleagues when he disagrees with them, where the rest of us would be more politic". But it would be easy to exaggerate dislike for him among his colleagues - it is most intense among those who don't know him or know how funny and personally loyal he can be. Those who visit Hartlepool attest to his popularity and assiduity in the constituency.
And on Thursday night, at Labour's party in Littleborough after the count, Ian McCartney, a Scot and as mainstream an MP as it is possible to find, made a gushing little speech, saying he hadn't known Mandelson very well before the campaign but he was full of admiration for the leadership he had shown, the way he had galavanised party workers and how, "when his reputation was on the line, he never buckled."
His tempestuous on/off relationship with the deputy leader, John Prescott is, thanks to their double act in running the by-election, in a decidedly "on" phase, presaging close co-operation in the run-up to the general election. And Prescott is not going to let Mandelson take the flak for what was a collective decision to focus the campaign on the Liberal Democrat candidate.
The by-election has also brought the first tentative steps towards another rapprochement: with the shadow chancellor, Gordon Brown. The rupture with Brown during the leadership contest last year was perhaps the most painful for Mandelson; the two had been very close; Mandelson talked up Brown to journalists shortly after John Smith's death, before coming out for Blair.
Ken Livingstone's view is that Mandelson has "core beliefs" but that he is "more interested in power than ideology". But that isn't quite borne out by the facts. Despite the brief youthful period in the Young Communist League, and a gap year working for a Trevor Huddleston project in Tanzania - he has since the late Seventies been steadfast in his politics. He was unequivocally a moderniser throughout the Eighties, but never dallied with the SDP - in contrast to his friend Roger Liddle, who defected, returned and is now co-writing with Mandelson a big book on Labour's future.
Mandelson's life is consumed by politics; but he is not hinterland-free. He swims and works out; he is a trustee of the Whitechapel Art Gallery and a governor of the English National Ballet. He is a pillar of the two blue-chip foreign affairs think-tanks, Ditchley Park and Chatham House. He has a wide circle of friends, many of them made during his time at LWT. But his culture, instincts and political personality are irredeemably Labour.
It has become fashionable to observe that Blair is terrific but Mandelson is the danger; that all the Labour leader needs to ensure a smooth ride between now and the general election is to cast the Luciferian Mandelson into the outer darkness. That isn't going to happen. Blair intends to use him in an essential, though as yet undefined, role in the campaign to return Labour to power. And not surprisingly so. Blair has a deep sense of Mandelson's contribution to keeping Labour afloat in the 1987 election campaign, which he ran as Director of Communications. It is ironic that in the demonology of the left, Mandelson is blamed for the failures of the 1992 campaign. For the whole election he was out of it, in Hartlepool.
After the victory, if there is one, his role will change. There is a fear on the left that Blair will make him a dictatorial chief whip. But Blair is much more likely give him a good ministerial job, probably in the rank immediately below Cabinet. Mandelson is known to be keen on the Foreign Office - possibly as European minister - or the Treasury. But that won't stop Blair consulting him after the election. The party leader is steadfast; not just because he is a close friend, which he is, but because he has a just and unshakeable conviction that the section of the political community which would most rejoice at the eclipse of Mandelson would be the Tories.