Cameron failed because he stuck to what he believed in

David Cameron was always an open book. As prime minister he was talkative and straightforward. Many times, I am told, when there was a Downing Street meeting to discuss a leak inquiry there would be an embarrassed shuffle from the prime minister. “Actually”, he would say, “that might have been me – I was sitting next to so-and-so at dinner…”

That means there is little new in his memoir, For the Record – certainly not in the extracts published so far. He didn’t like the way Michael Gove and Boris Johnson fought the EU referendum campaign against him. He is proud of legislating for gay marriage.

He and his book are different from Tony Blair and his book. Blair concealed his inner workings, and so when he wrote so candidly about the layers of calculation by which he managed his political relationships, above all with Gordon Brown, it came as a revelation.

With Cameron, though, it was all out in the open. The central relationships of his time as prime minister were transparent. His partnership with Nick Clegg was even written down in a coalition agreement and depended on the mutual understanding of two similar and mostly predictable characters. His partnership with George Osborne was also easy to read and even more harmonious.

So when the end came for Cameron, his failure was rather more vivid than it has been for most prime ministers. With characteristic directness, he resigned the morning after the referendum was lost. This honest acceptance of failure has paradoxically generated one of the silliest memes of public opinion: that Cameron “ran away” after his defeat. Imagine the hysteria, some of it no doubt from the very same people, if he had tried to cling on to power and to implement a policy in which he patently did not believe.

Indeed, it was the depth and sincerity of his belief in EU membership that was his undoing. Even those Remainers who blame Cameron for holding the referendum in the first place should recognise that.

But the idea that it is Cameron’s “fault” that the people voted to leave the EU is another myth about his time as prime minister. This one is harder for Cameron to rebut, because there was undoubtedly an element of party political calculation in his promise of a referendum.

If he had not made that promise, the democratic pressure against EU membership would have diverted more of the Tory vote to Ukip, and Ed Miliband would have become prime minister in 2015. The Tories would have become a Eurosceptic party to get the voters back, promising a referendum, which would have been held whenever Miliband’s minority government fell.

As with so many prime ministers before him, Cameron was brought down by hubris. He did the brave and right thing in allowing Alex Salmond to hold a referendum in Scotland, and won it, becoming over-confident. Just as Gordon Brown was done in by the business cycle he thought he had abolished – “no more boom and bust”, followed by a global financial crash – and Blair brought low by assuming genocidal tyranny could be defeated in Iraq as easily as it was in Kosovo.

Thus Cameron had six years, and his achievements seem thin. He restored the public finances, although probably by making deeper cuts to spending than were needed. And I would argue (indeed have argued) he did the brave and right thing in holding a referendum on Europe.

If he had been as unprincipled as his detractors allow – or even as Eurosceptic as I thought he was when he became prime minister – he should have campaigned to leave, after the failure of his renegotiation of the terms of membership. He would probably still be prime minister now.

But that wasn’t what he believed, and he paid the price for sticking to his beliefs. Just think of that the next time someone complains that politicians have no principles.