What is it about the London Mayoralty that seems to make it the perfect target for apparent mavericks?
Livingstone won it against the Labour Party (and having rejoined them is still a bit semi-detached), Boris Johnson (though by no means a certainty for the Tory nomination) is a standing embarrassment to his party, and now Brian Paddick is being heavily touted for the Lib Dem nomination.
He's an interesting proposition, especially in contrast to both Livingstone and Johnson: I'm no position to judge whether his willingness to speak truth to power is a foolhardy transparency or publicity-hunting, and I'd be worried if this turned out to be all about a private row within the Met; but his approach to difficult questions certainly appears more thoughtful than either Livingstone or Johnson, and more honest than at least one of them.
I wonder, though, whether he could possibly have what it takes for such a strange job. On the one hand, the Mayor has the largest single direct electoral mandate in the UK; on the other, the Mayor doesn't have that much direct executive power, just a share in some power over some local services (the big exceptions being road traffic management and the buses). For the job to work, you have to be good at knocking heads together, twisting arms and charming the pants off a very wide range of people and agencies who do have the executive power: and at persuading them that your idea was what they were thinking of all along.
That much may be common to most political processes, but it says something that, clearly, the Mayoralty just doesn't seem to fit into the conventional political career ladder: most people already in local government in the London boroughs don't have the political profile, most people who are already MPs probably see it as a side-show.
That can only be a good thing if it opens up conventional thinking and expectations about the political process: but forcing potential office-holders to be tested and tried in the boring details of government is the strength of our present system. The individualist outsider, surfing in on the wave of "None of the above", hasn't always been a great advertisement for the US system: but then, that's no doubt why the Mayoralty has been designed the way it has.