By relying exclusively on his reputation for competence, Cameron has become particularly vulnerable to political scandals.
By Ian Dunt Follow @IanDunt
The fear is in the eyes. That's the meaningful thing about David Cameron's recent performance. The mask slipped a bit and you could see the fear in the eyes. It was there for the last two PMQs, it was there for last Friday's emergency press conference and it wasn't completely gone by the time that he offered the Commons his statement on the phone-hacking inquiry.
The last fortnight has been the most damaging of Cameron's premiership, specifically because it threatens his primary electoral attribute: perceived competency. This quality is all he has to protect him from a public which has no idea what he stands for.
That absence of mission explains why he was unable to secure a majority, even in the face of a bitterly unpopular Labour administration in Downing Street. At the heart of the Cameron machine there is an absence. His survival strategy is based on sounding moderate and reasoned while the nuts and bolts, the actual politics, remain heavily slanted to the economic right.
This was evident throughout his time in opposition. His conference speeches were based on a wild-eyed obsession with the state. When alone with the Tory faithful, his angry tirades centred relentlessly on health and safety and employment regulations and anything else that didn't fit his free market agenda.
His usual speeches were of a different order altogether: riding with huskies, hugging hoodies, making soothing, modern noises on gay rights and the environment. Even where policy stuck to the Tory tradition, such as on Europe and crime, it was couched in controlled rhetoric which had escaped the Tory leaders that came before him.
A dichotomy existed: the extremist anti-state agenda, of which obsessive supply-side economics is the financial aspect, contrasted sharply with the moderate self-promotion pursued through his years in opposition. The public smelt a rat.
In No 10, the extreme politics remains, but the moderate speeches were substituted with a chairman-like approach to current affairs. He appeared constantly to appear above events. While an extreme privatisation agenda is rammed through parliament, Cameron always appears reasonable, centrist and, most importantly, untouched.
From Defra to the DoH, the only flack he ever faced centred on why he allowed the minister in question to go so far. Caroline Spelman took the slack over the forestry sell-off while Andrew Lansley took it over NHS reform. In both cases, Cameron was criticised for being too 'macro', for allowing his minister too much freedom - but never for actually believing in the policies, which he quite plainly did. Ever the PR man, he had separated himself from the reality of his politics.
Cameron's chairman image accomplishes the same purpose as his 'soft and moderate' message in opposition. It executes a political strategy which is unacceptable to the public while covering it with a branding package which is more attractive. The trouble is it doesn't work. The public might not consider him a fraudster, but they are left with no sense of who Cameron is or what he stands for.
Cameron's reluctance to elucidate his purpose in public sucks his political position of meaning. It forces him to rely exclusively on his greatest asset: the image of competence, the poise of the prime minister. He does this tremendously well, far better than many of us gave him credit for before last May. The problem is: when it slips he's got nothing else.
It slipped this last fortnight. This is not entirely surprising. He struggled as plainly during the 2009 Conservative conference, when his Europe policy came under severe strain in the heady rush of the news cameras. When a scandal turns into a full-blown political storm, Cameron has a tendency to wilt under pressure. The nervous eyes, the fatal misjudgements over how to grasp the agenda, the evasive manoeuvres in the face of persistent questions: Cameron does not perform well under pressure. That much was clear the moment he made yet another speech on the 'big society' while the Commons was rammed with MPs debating phone-hacking last Monday.
When your entire political reputation rests solely on the perception of competence, you'd better make sure you're presentable.
Contrast that with Ed Miliband, who is never going to beat Cameron in the image stakes. He photographs badly, people are irritated by his voice and his mannerisms are all over the place. But the last fortnight showed what can be made of an opposition leader when they correctly assess the extent of an issue's significance and act with resolve. All of a sudden, image and poise do not apply, because they feed through by virtue of one's political actions. Miliband did not have to look prime ministerial when he took Cameron apart at PMQs. He just had to ask the right questions and the image followed.
Cometh the hour, cometh the man, and all that. A few more hours like this and our assumptions about Cameron and Miliband might be liable to change.
The opinions in politics.co.uk's Comment and Analysis section are those of the author and are no reflection of the views of the website or its owners.