There have been plenty of fascinating revelations in Tony Blair's much talked about new memoir A Journey: toe-curling stories about his love life with wife Cherie, the admission that he was a sucker for the "beautiful princess" Diana and, most oddly, the shock news that he "couldn't live in a culture that doesn't respect [the bathroom]". But there's one passage which truly makes the reader do a double take. On page 555, Blair enthusiastically proposes the U2 frontman Bono as a head of state. "Bono could have been a president or prime minister standing on his head," he writes. "He had an absolutely natural gift for politicking, was great with people, very smart and an inspirational speaker. I knew he would work with George [W Bush] well, and with none of the prissy disdain of most of his ilk."
Apart from the natural comedy value of Prime Minister Bono answering questions about defence policy by handing out a copy of the U2 album How to Dismantle an Atomic Bomb, it's actually not such a fanciful idea. After all, Bono's activism, particularly his work in Africa, has earned him a Nobel Peace Prize nomination. And though REM's Michael Stipe may have once said that music and politics don't mix - despite having World Leader Pretend in their lengthy discography - it is worth asking what voters look for in their leader. Someone charismatic, good with a crowd, emotionally intelligent and (whether we like to admit it or not) well groomed. Someone who people believe in and can either identify with or aspire to. All traits you could just as easily attribute to Coldplay's Chris Martin as Barack Obama.
Actors such as Arnold Schwarzenegger run for office all the time. Some - like Ronald Reagan - make it all the way to the top. So perhaps it wasn't that much of a surprise when Wyclef Jean, who rose to fame with one of the most popular hip-hop groups of all time, The Fugees, stated his intention to run for President of Haiti earlier this year. "People will say, 'Man, Clef, what does he know about politics?'" he said. "All I know is I'm a natural leader and I will surround myself with top-notch policy experts."
Whether a completely devastated country actually needed a 37-year-old pop star, hitherto more famous for Fu-Gee-La and Ghetto Superstar, and who left Haiti when he was nine, was not the point. Pop stars do, after all, like to foster a faithful following, as do hopeful politicians. And so casting himself as the salve with which Haiti could be healed wasn't as incongruous as it first seemed. "I'm not a politician," he told Time magazine. "What I'm going to do is be a leader of the youth of Haiti and the people of Haiti."
Jean would probably have had the best campaign song, too, if he'd actually been allowed to stand: the Haiti electoral commission scuppered his plans to "transform music into policy" by disqualifying him on a residency technicality last month. Jean intends to appeal, but his chances are said to be slim. Still, you do sense his intentions were good rather than just born of a narcissistic urge for power. Jean could also heed the example of Peter Garrett, of the rock band Midnight Oil. One of Australia's most famous musical exports, widely known for the international hit Beds are Burning, the band had always been keen to emphasise the political element to their music: Beds are Burning itself is a plea for land to be given back to native Australians. But Garrett was so keen to be an activist, he actually broke up the band in 2002 to concentrate on a political career - at the very time they were enjoying more international exposure than ever. And he's been incredibly successful. Since 2004, Garrett has been an MP in the Australian House of Representatives, and until the recent election the minister for Environment Protection, Heritage and the Arts.
Sonny Bono, of Sonny & Cher fame, perhaps wasn't in the same charisma league as Bono or Wyclef Jean, and certainly didn't come anywhere near a presidential nomination either. But he did make it to Washington DC, becoming a Congressman for California who happened to have a No.1 single. While in the role, he extended the amount of years songs remain in copyright, but incumbent President Bill Clinton was hardly quaking in his boots.
At least Sonny Bono managed to transfer record sales into votes. As the least charismatic member of the Britpop band Blur, the drummer Dave Rowntree wasn't starting from a particularly strong base, despite having a readymade campaign song in There's No Other Way. But as a Labour candidate he has lost three times in elections: most spectacularly in 2008 when the safe seat he was contesting swung to the Conservatives in embarrassing fashion.
So as much as Blair suggested Bono would make good prime minister material, history suggests that it won't happen, simply because the leaders of countries are usually boringly professional politicians on upward career arcs. Somehow you can't imagine Bono sitting in some crushingly ineffective manifesto meeting or pronouncing on a pathetically minor element of housing policy from behind his sunglasses.
The level at which we should take seriously the political aspirations of most musicians, then, is summed up by the British pop star Dizzee Rascal. He was memorably asked by the hard-hitting political interviewer Jeremy Paxman whether the Obama phenomenon could be replicated in Britain. "Why don't you run for office?" proposed Paxman. "That's a very good idea, I might have to do that one day," he smiled. "Dizzee Rascal for Prime Minister, yeah?"
And if that sounds, well, Bonkers, then Jay-Z's much-publicised friendship with Obama suggests a hip-hop president is not such a ridiculous idea in the United States. After all, if Ronald Reagan can star in an Oscar-nominated film, and, 40 years later, be the self-styled "leader of the free world", anything is possible.