Joan Smith: My name is Gordon and I used to be the next PM

Hague's fortunes have turned since he failed to get the top job

Last autumn, I was astonished to find myself telling anyone who would listen about my new-found enthusiasm for Al Gore. Eyebrows were raised when I described the former vice-president, a notoriously wooden performer when he was Bill Clinton's sidekick, as witty, passionate and relaxed. But that's exactly what he is these days, as movie audiences will find out this week when a documentary about his campaign to halt climate change opens in American cinemas. The film, An Inconvenient Truth, follows Gore as he travels the US, showing his slide presentation - I know, but bear with me - which is by turns astonishing, terrifying and very funny.

I hope it includes his dig at Creationists, which consists of Gore superimposing two tiny naked humans, representing Adam and Eve, at one end of a chart showing the earth's lengthy evolution. On the occasion I heard it, in the presence of Gordon Brown, Gore also made a joke about knowing what it's like to be number two and having to listen to someone else take all the credit for your best ideas. I couldn't help thinking that if his performance in the 2000 presidential election had been half as accomplished, he might have won by a sufficient margin to prevent George Bush stealing the result, and a lot of people who are dead would still be alive, since it is unlikely that Gore would have started an unwinnable war in Iraq.

His renaissance is so spectacular that he is now being discussed as a presidential contender in 2008, a prospect encouraged by his recent joke on American TV that he is "a recovering politician ... but you always have to worry about a relapse". But comparing his current popularity with that of Bush, who is despised even by people who elected him in 2004, he may decide there's something to be said for staying in the category of men who would have been great presidents - just as R A Butler, Denis Healey and William Hague would, allegedly, have made great prime ministers.

Hague is another politician whose fortunes have turned since he failed to get the top job. In his diaries, Robin Cook observed that Hague "performed very impressively at Prime Minister's Questions but still sank like a stone in public estimation". But since stepping down as Tory leader, Hague has made a lucrative career on the after-dinner circuit, and recently returned to the Conservative front bench as shadow Foreign Secretary. There is an element of bad timing here: Hague took over immediately after a shattering electoral defeat when it is hard to see how anyone, however gifted, could have turned the tide running against the Conservatives.

Some people do not perform well under the relentless pressure that goes with seeking high office. The longer Gordon Brown waits, the grumpier he seems to get, although he is no more entitled to become prime minister than anyone else, having yet to tell the country why it should vote for him.

Brown should give some thought to the way Blair's reputation has plummeted since 1997. He has the opportunity to be remembered as a great Labour Chancellor, a much more successful politician than Gore during his period as vice-president, and he's mad to risk his reputation by trying to oust Blair from a job he may turn out to be unsuited for. As Gore gets ready to appear at the Hay Festival, Brown should reflect that the smart course is to settle for what he's already achieved and surprise everyone by stealing one of Gore's best lines: "My name is Gordon Brown, and I used to be the next prime minister of Great Britain."