One strange thing about the reception of Tony Blair's memoir is that Labour people have run screaming for the hills, while Conservatives have been speed-reading it for lessons in How to Do Government. The Labour leadership candidates have competed to distance themselves from the fastest-selling British political book. David Miliband said that Blair and Brown's "time has passed"; his brother Ed repeated yet again that it was time to "turn the page". But not of this book, naturally.
One Conservative cabinet minister, on the other hand, having read the extracts and the first few chapters, told me that, "if it were possible for the ardour of my Blairism to deepen, it has done so", and that a research assistant would be despatched to Waterstones on Wednesday to queue up for a signed copy.
For some of David Cameron's inner circle, the book will replace Lord Gould's 'The Unfinished Revolution' as their instruction manual. Gould, who was Blair's opinion pollster, provided them with a template for how the "heir to Blair" should claim his inheritance.
And so it came to pass. Sort of; a coalition in a hung parliament, anyway. Now they have a guide from Blair himself to what to do with that inheritance. They will "devour" it to give themselves strength, as Blair says he did of Cherie's love on the night after the death of John Smith.
Cameron became Prime Minister by following the Blair play book. He seized the leadership of his party by offering to help to implement the Labour government's school reforms. As leader of the opposition, he moved the Tories into the centre ground by contradicting popular assumptions about the party on the environment, gay rights and the NHS.
In the hours after the election, Cameron turned the indecisive result to his advantage with a "big, bold and comprehensive" offer of a coalition with the Liberal Democrats – just as Blair had planned to do, although the size of his landslide in 1997 made it pointless.
As Prime Minister, Cameron has sought to learn the lessons of the Blair years. Knowing that his predecessor-but-one felt that he had taken too long to get to grips with the Whitehall machine in his first term, he and Nick Clegg hit the ground at a cracking pace. They have launched huge changes to the benefits system, the NHS and schools at the same time as trying to cut spending more deeply than expected, and while running an early referendum on changing the voting system.
My Cabinet minister quoted from Blair's page 18: "We were very quickly appreciating the daunting revelation of the gap between saying and doing. In Opposition, the gap is nothing because 'saying' is all you can do; in government, where 'doing' is what it's all about, the gap is suddenly revealed as a chasm of bureaucracy, frustration and disappointment."
The problems of overcoming "inertia and the difficulty of bureaucracy" were things they "knew intellectually", but were now experiencing practically, this minister said, and here was the handbook. Only it is not really a management tutorial for the delivery of change; it is more of a leadership manual, and is thus aimed at Cameron himself. Yet Cameron, for all his superficial similarities, is not like Blair at all. He will never replicate Blair's leadership style.
What comes through Blair's book clearly is his remarkable sense of his own importance. Now, of course, all politicians feel the pull of destiny, and for most of them this feeds an almost infinite capacity for self-delusion.
For a very few, however, this sense of their own importance is not exaggerated. Blair thought he was something special even in his unsuccessful attempt to be selected as a candidate for Hackney borough council in 1982, and the book charts his growing certainty that "I can see it and I can do it".David Cameron had been talked about as a potential prime minister since working at Conservative HQ in his early twenties.
But there is a difference. It is the difference between the "great clanking balls" theory of leadership and the "doctrine of the right time" theory. Blair tells the readers of A Journey that he admired Alastair Campbell, he says, because he had "great clanking..." Er. And he attributes the same quality to himself, as he subjects himself to a degree of analysis that no other politician has done, apart from Barack Obama, a precocious autobiographer at the age of 33. With an unBritish boastfulness, Blair identifies in himself an "instinct" for politics.
It is an instinct for taking risks, for deciding when to go out ahead of the pack knowing that the people and party would follow.
Cameron has a feel for politics too – in addition to the easy charm and centrist modernism of the basic Blair skill set. But in his case, it is a more bookish, a more passive, understanding of when to seize the moment. Thus Blair rewrote Clause IV of the Labour constitution, went out on a limb over Kosovo and took on his party on student finance.
But Cameron has built his career so far on the opportunities that presented themselves to him. He saw the chance in Blair's academy schools policy to split Labour and present himself as the reformer.
Yet he failed to "detoxify" the Tory brand in the way that a Blair figure would have tried to; he thought he had done enough to win and so did not challenge his party over inheritance tax cuts or Europe, which might have shifted the Tory party fully on to the centre ground and won the election outright. But when the hung parliament presented him with the chance to finish the job, he took it, and took it well.
However good a politician Cameron is, therefore, his leadership is likely to remain essentially a reactive one. And that may not be enough to get him through tough times ahead.
John Rentoul blogs at: www.independent.co.uk/jrentoul