In the early Eighties, there was a scandal in the Irish Republic: financial and sexual shenanigans involving the then Attorney-General. The PM, Charlie Haughey, himself no stranger to shenanigans, tried to distance himself by describing the situation as “grotesque, unbelievable, bizarre and unprecedented.” That was quickly abbreviated to Gubu. it is time to resurrect that acronym, for today the Tory party is stranded in the Gubu desert.

David Cameron’s friends and admirers are in a state of shock. There is an aching sense of loss. It was bad enough that he proposed to resign in the course of this Parliament, but now, with so much undone, so much promise that will remain unrealised: most thoughtful Tories are Gubu-smacked.

There is one major omission which he may be able to address once out of office: explaining himself. Mr Cameron has been at the forefront of British politics for eleven years. Yet large numbers of sensible people still insist that they do not know who he is or what he stands for. That is very strange, because he is not a complicated man, especially by the standards of senior politicians. For a start, he is happy in his own skin. He has deep roots in a comfortable background in the Oxfordshire countryside – without being the prisoner of that background. His parents believed in simple values: hard work, public service, family – and fun. Freud said that to be happy, a man ought to be able to love and to work. In that sense, without realising it, David Cameron’s parents brought him up as a Freudian.

That was one of his few contacts with continental intellectuality. David Cameron has a strong and clear mind. At Oxford, while never a slave to his books, he got a high First. One of his principal tutors, Vernon Bogdanor, says that his marks were good enough to try for All Souls’. Those who have worked closely with him as PM are unanimous. Although he never vaunts his first-class intellect, it is always apparent. He cuts through the detail, moves effortlessly to the nub of the argument and takes decisions easily, though never hastily, with complete intellectual self-confidence.

He also surrounds himself with able people. Downing St has never been more formidably staffed. Credit is due all round, but especially to Edward Llewellyn, the PM’s Chief of Staff. Tireless, formidably calm, superb at judgment under pressure – and it always is pressure – he is one of the finest public servants of recent decades: the Platonic idea of a Chief of Staff. So: immense amounts of sinewy . tough-minded intellect, headed by a PM who has little interest in abstract ideas. Some Tories complained that the 2005 Election manifesto lacked philosophy. David, who wrote it, said: ‘if people want philosophy, let them read Descartes’ (he had read some Descartes, as part of the philosophy section of the PPE course}. His interest in politics owed little to philosophy and far more to practicality plus the instincts and prejudices of a traditional Tory.

To paraphrase de Gaulle, he always had a certain idea of Britain. His Britain was a nation of able, energetic people, far too many of whom were unable to realise their potential. He wanted to remove the barriers. He once said that his overriding goal was to leave the nation stronger and its people more prosperous: hardly an ignoble ambition.

Yet there was a problem: the legacy of Margaret Thatcher. She showed no reluctance to have dealings with continental intellectuals, or at least to quote the titles of her books. Plenty of her Tory predecessors had been intellectuals. She, whose intellectual credentials were much more dubious, was the first Tory leader to use the word ‘intellectual’ as an unalloyed compliment. The same was true of ideology. All previous Tory Premiers would have regarded that as a thoroughly dubious notion, redolent of bearded foreigners. She was pleased to believe that she had an ideology. That said, many of the ideas which she propounded had only a distant relationship with what she actually did; her words and her deeds often seemed to inhabit different planets.

But Lady Thatcher left behind a party which was nostalgic for her visions and inspired by her dreams. That was a difficulty for David Cameron, who did not do visions and who thought that the best place to have dreams was in bed.

He came to politics via the Conservative Research Department, a nursery of Tory talent. CRD has produced umpteen Cabinet ministers and several supposed future Prime Ministers who never quite made it. David Cameron was the first who actually reached No.10. By the time he arrived in the late Eighties, the glories of the Thatcher era were coming to an end and the government was increasingly embattled, as it remained until the crashing fall in 1997.

As young politicians do, David Cameron spent long evenings talking and arguing politics. He and his friends had endless discussions about the same topics. From Wilberforce onwards, the Tory party had a great reforming tradition, as could be demonstrated by the record of Tory governments. Yet Tories never received any credit for this. Mrs Thatcher had spent like a social democrat: the political upshot, the myth of Tory cuts. The Tories were seen as a club for the uncaring rich: the party of the man with no heart.

That was all survivable as long as the Labour party was dominated by threatening Lefties. The man with no heart will usually beat the man with no head. Then came Tony Blair. His gifts of political presdigitation enable him to toxify the Tory brand while stealing Tory themes. When focus groups were asked about a particular policy, they might well say “that sounds a good idea”. They would then be told that it was a Tory idea. “In that case, there must be something wrong with it.”

People seemed unwilling to accept that the Tories cared about ordinary people’s schools and hospitals; they would never dream of using them. David Cameron and his friends appeared to be facing the prospect of permanent opposition. So policy and politics came together. Mr Cameron was determined to transform his party’s image in every respect. That done, he hoped to be able to persuade a majority of voters that the Tories had humane priorities.

There was a paradox: David Cameron, an Old Etonian, determined to succeed where Ted Heath, Margaret Thatcher and John Major had failed. But he certainly succeeded in reshaping his Parliamentary party. Women, homosexuals, ethnic minorities; this is a transformation unequalled in political history. There has been one failure: MPs from a Northern working-class background. A few more of those might have made a difference last Thursday (not that there are many of them in the Labour party either).

When it came to policies, there was no shortage of innovation. The priority given to environmental issues has controversial aspects. It is hard to believe that onshore wind farms have contributed to either the economy or the landscape. “The Big Society” is big in name, not in outcome.

But there have been achievements in two crucial areas which her late Ladyship sidestepped. The first is education. The drive for free schools, academies and higher standards in general has led to changes that are cultural as much as legislative. For more than forty years, unimpeded by Margaret Thatcher, the Gramscians had been on a long march through British education, destroying good schools, sabotaging standards and ruining the life chances of many children. Now, that process has at least been halted.

Yes, Michael Gove deserves a lot of credit, but David Cameron always stood behind him. It is worth remembering that after the 2005 Election, when Michael Howard offered him a choice of shadow cabinet posts, David chose education. David moved Michael Gove for a sound reason: that his propensity to pick unnecessary quarrels was undermining the success of his policies.

The second vital change was in welfare. Here, Iain Duncan Smith provided moral drive, although he was unable to translate that into bureaucratic competence. But IDS did help to change the culture. For decades, the welfare state had often been an ill-fare state, sucking poor youngsters into a dependency culture which often became hereditary. That is now changing.

Few Prime Ministers can choose the wicket on which they have to bat. By temperament, David Cameron was a leader who would have enjoyed dispensing glad tidings. He would like to have stolen Roosevelt’s Happy Times Are Here Again (not that it was true for much of Roosevelt’s America, at least until the War). In opposition, he had talked about sharing the proceeds of growth. But there was no growth. David was forced to become an austerity Prime Minister. With the help of George Osborne, who always had ice in his veins even in the darkest hours and whose macro-economic judgments were vindicated even while he tripping over the odd Cornish pasty, David Cameron led the country out of the valley of the shadow of recession. We shall have to see what happens now.

The achievements are considerable, as will become apparent when the European degringolade no longer dominates British politics (that will be the day).

But there was one recurrent weakness. Mr Cameron never explained himself. Of course, he made many good speeches. Whenever there was a political essay crisis, he would sport his oak, brew a cafetiere, work through the night, and produce what was needed. Yet there was never a narrative: never a running theme which would help the public to understand what the government was about and who the Prime Minister was.

Now, however, there is a further paradox. Although Europe has just seen off a third successive Tory PM, David Cameron has never been more popular. If the British economy slides back into recession while it becomes clear that the Brexiters do not have a plan, expect growing calls for a Cameron restoration. David Cameron does not do repining and “if onlys”. He has no wish to be a PM over the water. But he is not yet fifty. It is hard to believe that his career in public service is over. On all rational calculation, the UK now faces several crises, both economic and constitutional. Traditionally, the Tory party regards itself as the true national party, the country’s rock. But that needs leadership. Can the Tories provide it, or will Gubu prevail? Or will Cameron return?