John Rentoul: Caught out, but he's clever

We have all done things that might embarrass us later. In my case, I was working on updating a biography of Tony Blair when I caused Boris Johnson to become greatly excited. He knew someone who had known the future Prime Minister during Blair's gap year between Fettes College and Oxford. The 18-year-old Blair, long-haired, bell-bottomed, sometimes barefoot, had come to London to make his name in the music business. Johnson was convinced that Blair had smoked dope in this bohemian period, and that, if he persuaded me to speak to enough people, one of them would confirm it. It would be a terrific story. I could put it in my book and he could print it in The Spectator first. The problem was that no one would confirm it, on the record or off, first-hand, second-hand or simply made up. Indeed the testimony of the people who knew Blair in his gap year was precisely the opposite, and thus consistent with that of his school friends before and his university friends afterwards. What was notable about him, they said, was not that he tried drugs, but that he did not, despite hanging out with the sort of people who did.

When I relayed this information to Johnson, his crest was fallen, but only briefly. Because along came Ann Widdecombe, who was at that time shadow home secretary. At the Conservatives' annual conference in 2000, she proposed a policy of zero tolerance of cannabis. The representatives applauded, but journalists then had the most fun they had had since they were young, asking other members of the Shadow Cabinet if they had always practised what Widdecombe preached. They turned out to be surprisingly eager to confess to past transgressions, not least because many of them wanted to kill what they saw as a vote-losing, illiberal policy. One of them even complained to a colleague of mine: "No one has rung me and I smoked loads of dope at university."

It was at this point that Johnson became excited. Surely now was the time, with leading Tories queuing to tell all, to flush out that elusive witness to Blair's druggie past? But no such person came forward, then or later. Johnson's search for a sensational story was frustrated and later found a rather different outlet, with him at the centre of it.

His excitement was understandable. If someone had said that they saw Blair with a spliff, it would have been a huge scoop. But it is important to be clear why. It would not have been primarily because the Prime Minister had broken the law as a teenager, but because, in 1994, he had denied having smoked dope.

The trouble was that he had added, "But if I had, you can be sure I would have inhaled", a reference to Bill Clinton's answer to the same question. To people like Johnson, it seemed to dilute the denial. As Blair said last week in a podcast interview with Stephen Fry: "Never try to do irony. I have tried it once or twice and it has never worked, in front of a camera or a microphone."

As the Shadow Cabinet's mass confessional suggested, however, attitudes were changing in 2000. Provided that drug use could be locked and bolted in a box marked "youthful experimentation", and provided it formed part of a story of a politician's life that held together, it need not cause damage.

Even in US politics - often more puritanical than our own - George Bush was about to be sworn in as President despite his refusal to answer questions about cocaine. "When I was young and irresponsible I was young and irresponsible," Bush said, and David Cameron used different words to say the same thing when he ran for the Conservative leadership just over a year ago. Cameron said: "I did lots of things before I entered politics that I shouldn't have done", and our revelations today about his drug-taking should not reopen that box. As with Blair, the danger for Cameron was never the original offence but that of being caught out by his own words - in his case, the definition of when he "entered politics". Did he mean when he was elected as an MP in 2001, or when he joined the Conservative Research Department straight from university in 1988? Either way, the news that he smoked dope at Eton does not put his words to the semantic test. More than that, the portrait painted by my colleagues James Hanning and Francis Elliott in their forthcoming biography of the Tory leader is that of a whole person. If today's extract presents Cameron as unusual, it was the élite boarding school rather than the dope that was out of the ordinary.

Attitudes continue to change. Yesterday, Barack Obama announced he was running for the White House. He may still be in fourth place among credible presidential hopefuls at this early stage, behind John McCain, Rudy Giuliani and Hillary Clinton. But he is credible - despite volunteering a rather franker account of his past drug use than any other front-rank politician on either side of the Atlantic. His memoir, Dreams From My Father, includes a striking passage in which he describes - unusually - in the second person how he got through a bad patch of late adolescence. "Pot had helped, and booze; maybe a little blow when you could afford it. Not smack though." In other words, he did cocaine, but not heroin.

What is important about Obama's book, though, is not that he takes the art of the pre-emptive political confession to a new degree, but that it forms part of a believable story about why he decided to put it all behind him. He is now inoculated against more bad stuff coming out from that period of his life.

The same principle applies to Cameron. When he refused to be specific about things he should not have done when young, most people must have assumed something more serious than trying cannabis at school. The Widdecombe tendency in his own party may not disapprove of him any less, but the rest of us will not disapprove any more. To the extent that Cameron's character has been established in the public mind, our exposé does not change it. On the contrary, it fills out the picture of a personality regarded more favourably than that of any Tory leader since John Major went down the pan.