This was a vital election. A Tory failure would have been an act of political treason. Five years ago, the UK was grovelling with the PIGS in the fiscal sty. Our public finances were in a deplorable state, the financial system was in crisis and growth had disappeared over the economic horizon. No one has paid enough tribute to Messrs Cameron and Osborne for the sang-froid they displayed in the face of such adversity, and for their success.

Not only that: we have two long-term structural problems in this country, both of which Lady Thatcher sidestepped, both of which David Cameron tackled. The first is welfare. In its corrosion of morale, its sabotage of élan vital, our welfare system creates an underclass. Any travel-stained kid with two legs, two arms, semi-competent English, an honest face and a willing manner can walk off a bus from Warsaw and into a job. So why do we have 1.8 million unemployed?

There is one obvious reason. To use Alastair Campbell’s contemptibly complacent phrase, we have bog-standard comprehensives, which turn out children only equipped to live on welfare. There again, the Tories acted, with the Gove reforms.

The radical changes in welfare — IDS’s agenda — and education are not just legislative. Within another five years, they will have changed the culture, in the same way that Margaret Thatcher’s trade union reforms did, and will be irreversible. That would not have been true if Mr Cameron had lost this election, which he came perilously close to doing — and it would have been his own fault.

There is one profound misconception about David Cameron. He began his career in that great political nursery, the Conservative Research Department. He then became a political adviser, and afterwards was alleged to have worked as a spin-doctor for Michael Green, though his role was broader. He spent many evenings around many dining tables discussing his party’s future. So when he became PM, there was a widespread assumption. Whatever else he did, he would be a superb politician.

That turned out to be entirely wrong. He has been a seriously important Prime Minister, with more to come. He may yet end up with a claim to greatness. But of all the post-Churchill premiers, he has been the worst politician bar two: Anthony Eden and Gordon Brown (yes, I mean it: not as good at politics as Alec Home).

As a politician, DC has one stonking defect. He is too normal. In William Waldegrave’s recently published and unputdownable memoir, he says that John Major was ill-equipped for prime-ministerial leadership because he was not ‘odd enough, ruthless enough or strange enough’. Something similar is true of David Cameron. He is too gently rural, philosophically pragmatic, eupeptically English. ‘Dearly beloved’ could be his motto. Churchill and Thatcher, the great warrior politicians, were seeking to compensate for inner incompleteness. David Cameron is seeking to express an inner calm.

That sounds impressive: not so. Most British voters are not inwardly calm. Many of them lead lives of quiet desperation. David Cameron’s self-assured body language grates on them and his background does not help. A lot of voters are ready to let social resentment tip over into voting behaviour. Mr Cameron is not the man to dissuade them, especially as his excessive rationality leads him to a combination of Heathism and vulgar Marxism.

‘Action not Words’ was the title of Ted Heath’s 1966 manifesto: the right phrase, if you were up against Harold Wilson — but not if you believe it. In politics, words are action. You need them to mobilise support. Although this does not mean chronic dishonesty, à la Wilson, you have to explain yourself. David Cameron is a highly articulate man, but he has been hopeless at explaining himself. Even after five years, millions of voters do not know who he is, what he believes, what are his values. Crucial arguments were never presented. How can anyone talk about austerity when the budget deficit is more than £70 billion? Given this government’s record, why should the NHS be a political liability? All this is maddening, because he has surrounded himself with formidable advisers. The personnel of the Downing St policy unit, plus closely linked special advisers such as Rupert Harrison at the Treasury, a future prime minister, were much the most impressive such grouping in British political history. Yet they were hardly allowed to brief anyone. As for David Cameron’s Downing Street press operation, since the departure of Andy Coulson, who was first-rate, it has not been worth Bernard Ingham’s fingernail clippings. Fortunately for the PM, he did have two other spokesmen working flat-out on his behalf: Ed Miliband and Nicola Sturgeon.

Like Margaret Thatcher and Tony Blair, David Cameron is a lucky politician. If Labour had been led by Alan Johnson and if the Liberal leader had sounded like John Arlott, the Tories could not have won this election, which would have been a disaster for the country. When he is accused of being an essay-crisis politician, the PM bridles. But it is true. Such is his self-assurance that he can relax in adversity, confident that when a big innings is called for, he can saunter out to the middle and score all around the wicket. He has never failed yet. Even so, he should be more considerate to those supporters who do not have his nerves of steel.

It should be easier for the Tories to win the next election. There is no reason why we should not have four years of economic growth at 2.5 per cent, which would make the country almost £200 billion richer. The northern powerhouse should be delivering northern votes. The deficit is manageable as is Europe. Scotland is a problem, but not for Toryism in England. Still without an economic policy, Labour will have to rely yet again on telling lies about the Tories’ plans to wreck the NHS. This assumes that a lot of voters are like eight-year-old children on a dark night, easy to scare with a ghost story. That is unlikely to work. Enough people will have noticed that the NHS has not been wrecked.

But the factors in the Tories’ favour would be even more effective if the PM would stoop to political conquest, devote time to explaining himself, and not wait for the essay crisis. Even if he sticks by his decision and does not fight another election, he could make life easier for his successor.