And in that key word lies the rub -- and Cameron's worst nightmare. The rise in prices on the Boris Index is a sign that many Tories are resigned to losing the next general election. The right, which has never wholly trusted Cameron's attempt to "detoxify" the party's image, is disgruntled; the center worried that a panicky "lurch to the right" spells electoral calamity. It remains rather easier to imagine Boris as leader of Her Majesty's loyal opposition than as prime minister. Indeed, even Tapsell only ventured that "perhaps" Boris could be a credible prime minister.
Boris is fun. But political prime-time is not the same as light entertainment.
So a large part of the pro-Boris bandwagon is predicated upon Cameron being ejected from office after a humiliating election defeat in 2015. Boris, back in parliament by then (even though his second mayoral term does not end until 2016) would then be swept into the leader's office by depressed Tory members who want nothing more than to be cheered-up.
It takes no great powers of political analysis to perceive that this would be a high-risk adventure. For instance, the idea of Boris ever -- even accidentally -- having responsibility for Britain's nuclear missiles is not a soothing one. But nor is it an idea that can be dismissed as evident nonsense.
For the time being, Boris is urging some measure of loyalty. "After 2016 who knows what will happen" he says. "But I'm very, very happy with the job of mayor of London." Discontented Tories -- i.e., his putative rivals -- should "cool their porridge" and "save their breath." They need to "put their shoulders to the wheel, all hands to the mast, and all shoot from the same trench -- to mix my metaphors."
And yet none of this quite convinces. Boris's relationship with Cameron has long been uneasy. Cameron was two years Boris's junior at Eton (and Oxford) and, befitting the time-honored conventions of the British boarding school, the older boy has never quite lost the sense of superiority first ingrained by seniority when the pair were teenagers.
It certainly seems that way. In an interview with a French radio station this month, Boris suggested, in his typical style, that he and David Cameron were "like Wallace and Gromit" though, as the Guardian observed, "he didn't say which was the absent-minded inventor and which his far brainier dog."
Be that as it may, many Tories still consider Boris the Clown Prince Across the Water. This despite a record of achievement that is, by objective standards, negligible. Boris has performed adequately as mayor of the capital city, but even his staunchest admirers are hard-pressed to produce any lengthy list of achievements he has to his name. London's mayor has relatively few powers. Like being governor of Texas, it sounds a weightier position than it really is. There is a fear that, just as the United States was lumbered with George W. Bush, so Britain could be stuck with Boris. Like Bush -- whom Boris once described as a "cross-eyed Texan warmonger" -- Johnson's appeal is as much a matter of style as substance. He talks "Real Tory." From his euroscepticism to his enthusiasm for lower taxes, Boris tickles the Tory party's erogenous zones. And he does so in a fashion that seems to entertain the public.
Perhaps it is a feature of these rancorous and gloomy times that Boris is no longer as preposterous a notion as he once seemed. He is not a "serious" politician but, as election results in Italy and Israel have shown recently, non-serious, populist, politicians are able to capitalize upon public discontent.
Before he became mayor of London, Boris briefly served as shadow arts minister in 2004. Upon his appointment he told one interviewer, that "Look the point is ... er, what is the point? It is a tough job but somebody has got to do it."
We may yet hear a variation on that refrain once again. Being leader of the Conservative Party is a tough job that someone has to do. So why not Boris?
The mind, as Boris might admit himself, boggles.