Monday night saw Michael Cockerell's much-hyped documentary on Eddie Mair's newly-christened "nasty piece of work", Boris Johnson. Much ink and Tory Party blood has been and will be spilled over the Mayor's squirming answers to the question of whether he'd like to be prime minister. The great revelation was that Boris would "have a crack at it" if "the ball came loose from the back of the scrum", as if this was telling us something that we didn't already know.
It's strange that the media regularly poses the question and then flaps itself into an outrage when the politician in the spotlight fails to give a straight answer. What we're asking Boris - and the endless list of other suitors for the top job, from Theresa May to Adam Afriyie - to do is the equivalent of telling a middle manager to stride into the boardroom, point at the CEO and say: "I'm coming to get you". In any job, it would be suicide, and we can hardly expect politicians to accept a one-way ticket back down the greasy pole.
The only reason interviewers ask the question is because they know it's a cheap shot. There's no good response: say 'yes' and kiss your ambitions goodbye, or say 'no' and everyone will think it's an inverted pyramid of piffle. The line of interrogation aims to paint politicians as shifty when - at least on this occasion - it's really not their fault that they can't give a straight answer.
However many classical or sporting analogies he cites, whatever his chances of being reincarnated as an olive really are, we all know that Boris would kill to be prime minister. But then, the same is true of almost every single minister and the vast majority of MPs. Politics is not always a glamorous game - an endless trudge of constituency surgeries in a wet office with a broken filing cabinet is a long way from dancing to the Spice Girls at an Olympics opening ceremony - and, more importantly, if you do want to help people, having power matters. A recurring gripe from backbenchers is that it's so hard for them to make any real difference; David Cameron runs the country.
People are naturally ambitious and politicians all the more so. Why should we expect them to sit there, contented with their lot, when so few of the rest of us are happy to let our careers pass us by? In any job, people want to be that rung higher on the ladder - why else would we see the proliferation of roles with inflated titles if not to keep us hordes of discontented workers happy? And if people if prepared to fight to the death to become the Sales Distribution Manager, no wonder that there might be a little bit of interest in a job that gives you the keys to an arsenal of nukes
It's little surprise that the Mayor emerges unscathed from this sort of questioning: although it makes him go hot under the collar, the public aren't stupid. They will hardly expect Boris to shoot himself in the foot for no good reason. The much more informative question - and the one which is much harder for politicians to answer - is not whether they want to be PM, but if they're up to the job.