Mr Cameron was one of two stars to emerge from the extraordinary party conference in Blackpool. The other helps to explain why Mr Cameron has soared at an unprecedented speed.
Tony Blair dominated proceedings in Blackpool, more so than he did in Brighton at his own conference the week before. Most of the leadership candidates paid homage in various ways, borrowing his language, hailing his public service reforms and acknowledging that they could not return to the pre-Blair era. Mr Cameron, in particular, seeks the Blairite mantle.
Some of his close allies speak of Labour's election-winning Prime Minister in hushed tones. One told me that he had read a book on the rise of New Labour "several times". Another carries an anthology of Mr Blair's speeches around with him more or less wherever he goes.
These Conservatives respect and admire Mr Blair far more than some of those who attended the Labour conference last week. In Brighton, some asked impatiently: When is Blair going? In Blackpool, they posed the same question but in a different context. Quite a lot of them have concluded they can never beat Labour while he is leader.
Mr Cameron responds to this perceived invincibility by saying more or less: "If you can't beat him, join him". Or to be more precise: "If you can't beat him, become him". The style is almost exactly the same, jacket off, relaxed informality, engagingly at ease with the media.
The political objectives are also familiar. Mr Cameron seeks to modernise his party. If he becomes leader, he will move fast to bring about change. A Cameron leadership would burst with energy. Very quickly, the Conservatives would look young again, a party renewed and more at ease with the changing world.
His early agenda would be very different from previous Conservative leaders. I am told that in the first few months Mr Cameron would focus on the inner cities, the environment, global poverty and public services. Immigration and Europe, two favoured themes of the past, would not get a look in.
Work would begin immediately to persuade local parties to adopt women candidates. At Prime Minister's Question Time, Mr Cameron would adopt a less adversarial tone. When he agreed with Mr Blair, he would tell him so.
If the right-wing newspapers disapprove of this more human approach to politics, Mr Cameron intends to hold his nerve. Mr Blair has noted privately that recent Conservative leaders have been badly advised by some of their newspapers. Mr Cameron has noted this, too.
Here are signs of fresh thinking that echo in some ways the rise of New Labour in the 1990s. The echoes, though, are not as loud as some Conservatives assume. Mr Blair was a much more rounded and experienced political figure by the time he acquired the leadership in 1994. Mr Cameron has only been an MP for four years. By far his boldest move in politics was to put his name forward for the current contest. He will be tested greatly and quickly if he gets the second most difficult job in British politics.
Young leaders tend to fail the test. Even after two years in the Cabinet, the young William Hague did not rise to the challenge. For Labour, the youthful Neil Kinnock suffered from crises of self-confidence at low moments in the 1980s. Perhaps Mr Cameron is made of sterner stuff, but neither he nor the rest of the Conservative Party are in a position to know for sure.
I continue to read what a triumph the conference has been, but it is a sign of the Conservatives' desperation that Mr Cameron is being hailed as the messiah on the basis of a successful launch and a single speech.
Even the most assiduous Conservative admirers of Mr Blair tend to underestimate what happened to Labour under his leadership in the mid-1990s. After the 1992 election, Labour's internal findings showed that, above all, it was still not trusted to run the economy. By 1997, it was widely seen as the party of economic competence.
This was the key to Labour's success. Its recovery in the 1990s was built on changes to economic policy and, in particular, a new approach to "tax and spend", the great vote-losing issue for the party in the 1980s.
Now the Conservatives face a similar challenge. Unless they meet it, the rest of Mr Cameron's agenda will fail to resonate. At the last election, they were not trusted in relation to economic policy, suffering once more from the fatal perception that their sums did not add up, a reverse of the 1980s.
At present, their aspirations, as expressed by most leadership candidates at their conference, still make no sense. The essence of the Conservatives' problem is that they seek Swedish-style public services with US levels of taxation. I heard nothing this week to convince me that both are possible. As Ken Clarke said in his speech this week, the current talk of modernisation is like a doughnut with a big hole in the middle. That hole is where a proper economic policy should be.
Mr Clarke dared to make some politically courageous points in his speech. In particular, he highlighted the dangers of promising too many tax cuts in advance of an election. In terms of substance, it was the best speech of the week. Mr Clarke is much tougher on public spending than I would be, but in relation to the modernisation of the Conservative Party he would restore quickly its reputation for economic competence. In this sense, he is closer to being the Conservatives' true moderniser, telling his party some home truths on "tax and spend" as Blair and Brown did to theirs in the 1990s.
In contrast, Mr Cameron and his friend, the shadow Chancellor, George Osborne, have expressed interest in a flat tax. They are too astute to adopt such a politically and economically disastrous policy, but they will give their opponents plenty of ammunition until they reject it. Messrs Blair and Brown gave their opponents no equivalent scope for attack over economic policy when they "modernised" Labour in the 1990s. Mr Clarke would not do so now.
But Mr Clarke does not look or sound like the young Mr Blair. Such was the range and intensity of the Blair fan club in Blackpool, I suspect that it is the youthful candidate who will win. The two stars of the Conservative conference may be facing each other across the Despatch Box in Parliament by the end of the year.Reuse content