One could certainly make a case for Superman Dave. The Conservative leader has ditched the past in a manner never achieved even by Pol Pot. Operation Apology has been followed through with a steely consistency. In the past month alone he has met Nelson Mandela and repudiated Margaret Thatcher’s ambivalence over the ANC two decades ago, laid a wreath at Gandhi’s grave in India and, in another foreign trip, visited Scotland to lament that the poll tax was imposed there as if its people were mere laboratory animals. Further, in an underreported speech, he condemned the English caricature of Glaswegians as aggressive alcoholics. Never mind “hug a hoodie”, attempting to “grope a Glaswegian” is a really bold strategy.

The Superman syndrome does not stop there. Under Mr Cameron the Conservatives have placed themselves at the cutting edge of webcam technology. What used to be a www.direlyboring.com organisation is of recasting itself as a www.hipandcool.com. His A-list reform of candidate selection, although open to the charge that it has achieved diversity in gender, ethnicity and sexuality at the price of uniformity in age, background and geography, is succeeding.

And, most important of all, he appears to have delivered a sustained advance in the opinion polls. What more could you possibly ask of a man before conceding him the status of a superhero?

Quite a lot. There are three reasons why this Superman sketch should attract suspicion.

The first lies inside those much vaunted opinion surveys. The evidence implies that what we have witnessed is less a “Cameron effect” than a “cock-up impact” on the electorate. The first three months of Mr Cameron’s leadership did, indeed, see a notable “bounce” in the Conservative Party’s ratings — although since the Liberal Democrat leadership was simultaneously imploding it is hard to be sure whether it was a “Cameron charge” or a “Kennedy crunch” that was occurring.

Between February and April, however, the polling figures had eased back almost to the point where Michael Howard had left them. Then along came the Prescott debacle, the spectacle of the Health Secretary being shouted down by nurses and, above everything else, the fiasco over the release of foreign prisoners. The Tories moved forward in the polls again, while Labour bled.

Yet it did not last. By July the two parties were almost at parity once more. The cock-up then emerged again, courtesy of the bombing of Lebanon, a terrorism alert that appears to have spooked voters into concluding that Tony Blair had made them a target and fratricide in the highest ranks of the Labour Party.

Despite all this, a YouGov poll on Saturday had the two parties level. The prediction that I made here in June, repeated in August, that the Tory poll lead would be eliminated “by September” has been vindicated (albeit at the last possible minute). It is less that the public has been seduced by a Superman than that ministers have been prone to periodic outbreaks of collective stupidity that explains the trends in surveys.

Then there is the style-versus-substance business. Mr Cameron could not be blamed if he feels that he is being treated harshly on this score. It is unreasonable to expect him to have even the skeleton of a programme now, never mind blood, flesh and muscle. To assume that because he has style he must be devoid of substance is crassly cynical.

In truth, Mr Cameron does face a dilemma over substance, but it is not the one that he has been accused of. It is how to keep control of the substance that will emerge from the multitude of policy commissions that he has established. For it is a lot easier to set up committees than it is to ensure that what they recommend is affordable, appealing or at one with other parts of election planning.

Furthermore, these bodies can be made to look interesting only if some independent people are appointed to them. Yet these are always the types who make the most noise if their proposals are rejected. There will still be a Tory substance problem a year hence, but it will not be because substance is missing.

Finally, there is the risk that Mr Cameron has chosen to take. He has travelled into territory well beyond that which modernisation makes necessary. He has adopted an approach to environmentalism more Albert Gore than Albert Einstein in its analysis of the scale of the challenge provided by climate change and the measures needed to tackle it. He plainly aches for the blessing of Friends of the Earth and Greenpeace. His proposal for binding annual targets for cutting carbon emissions is, potentially, the most statist suggestion made by a leading political party since Michael Foot’s manifesto in 1983.

In a similar spirit, he has taken it upon himself to bash big business and to distance himself from America in foreign policy. While there is a sound argument for the Conservatives embracing the “big tent” politics perfected by Mr Blair, Mr Cameron may be seeking to construct a marquee so vast that it eventually collapses.

Despite appearances, therefore, Mr Cameron is much more Clark Kent than Superman. The serious danger for him this week in Bournemouth and beyond is excess expectations. Once Tories no longer believe that their man can fly, will they remain inclined to follow him?

Times Recommends

• It’s the beginning of the affair
• Afghanistan: still a price worth paying
• Heroes of the downtrodden