The benefits of the Boris win to David Cameron are as obvious as they are potentially illusory.
With Labour gaining 824 seats and making deep inroads into vital constituencies in the Midlands and South England, a Conservative consolation prize was urgently needed.
But it appears Mr Johnson scraped home not so much because but in spite of his party colours.
He outperformed the Conservatives not only across the country, but also in the London Assembly itself.
And most informed commentators believe his success in gaining a second term as the capital's directly-elected mayor owes much to his effervescent manner and personal charm.
In short, it was Brand Boris wot won it. But that's far from all of the story.
Canny uber-Conservative BoJo has also spent many months more or less discreetly distancing himself from the Cameron-Osborne duumvirate at the head of the Tory party.
Sometimes as much by implication as by statement, and often to the irritation of Downing Street, he has positioned himself as the champion of traditional - as opposed to modernising - Tory values.
Hence the delicacy of the choreography associated with his victory twirl with the Prime Minister.
When it did finally take place the mutual murmurings of loyalty were audible. But in the body language the lack of affection was palpable.
All this will intensify speculation that, in spite of all his denials, what Boris really wants is the keys to Number 10.
Fanciful though that might seem at present, the grumbles from within the Conservative Party about David Cameron's style and policies are getting more menacing by the day.
And there is a baseline dictum in politics. What really matters is winning.
Which is what BoJo is currently doing. While Dave, in the view of many, is not.