Boris Johnson has form when it comes to destabilising Conservative conferences – and leaders.  In 2014, with the Coalition Government mired deep in mid-term unpopularity, the then Mayor of London was touted as a populist successor to David Cameron. “Bo-ris, Bo-ris, Bo-ris,” the crowd chanted as their hero arrived at Birmingham’s New Street station for the annual shindig, as he professed not to know what the fuss was all about.  “I’m here to support the Party,” he declared – only a few hours before tickling party members’ collective tummy with a speech backing grammar schools.  Five years earlier, when Cameron was in opposition and an election not far off, he had rocked the conference by urging a referendum on the Lisbon Treaty.

And now, the best part of ten years on, he is at it again.  We have seen the movie before: first, the boat-rocking briefings; next, the denials, stammered out with an artful hint of self-mockery; then the photos of Johnson out running, comic and dynamic all at once – with a hint of accessibility.  Finally, there comes the speech.

It can, in such circumstances, be a belter – and it must be said at once that his offering today out-trumpeted all the others so far on offer at this flat, bewildered and underwhelming conference.  But this was not precisely because he had crafted it as a crowd-pleaser, though it was certainly intended to wow his audience.  Rather, it worked because at its heart it was making an argument.  This was not merely that Brexit can be a stonking success, but that it is Conservative ideas that can make it so.  The Union flag, British troops in Nigeria, and hurricane relief in the Caribbean met fintech, cybernetics and clean energy.  Where Philip Hammond yesterday sombrely cited the 1970s as he warned of the Corbyn menace, the Foreign Secretary dismissed the efficacy of looking back, and cheered up his listeners with a bracing list of eastern European flat tax rates.  Where other Ministers strain to whack Corbyn with a bludgeon – and usually miss – Johnson reaches instead for the tickling-feather, and is all the more effective for it.

That the Foreign Secretary was putting a case rather than simply reciting a list of jokes is key to understanding what he is up to.  Of course he wants to be leader.  And of course his intimations of loyalty to Theresa May today will be discarded tomorrow.  But there is more to what he is up to than monomaniacal ambition.  His yearning for a move to Number Ten is wrapped up with frustration at being excluded from the core of Government decision-making, genuine Brexiteering conviction, a blazing urge to defend the Vote Leave campaign which he fronted and, most ominously of all for the Government, the belief that the Prime Minister is making a mess of the negotiation.  This bodes ill for her, and perhaps for him too.  He wasn’t sacked after pushing his boat out in the Daily Telegraph last month.  So he has pushed it out again.  And will push it out yet again.  And will do so again and again and again until it parts from May’s own, or sinks beneath the waves, or some unknown concert of events causes him to yank it smartly back in.

We are roughly where our readers are.  We cheer the Foreign Secretary for his conviction that Britain can hack it, that WTO trade with the EU wouldn’t be the end of the world, and for providing what this Conservative conference has completely lacked to date – namely, a strategic sense of direction.

But we also boo him, or at least come close to doing so, for not coming clean about the WTO downsides and risks, and for not finding a way of making his case within the Government rather than running for headlines to his Fleet Street cheerleaders.  In this month’s ConservativeHome survey, activists have put him top of our Next Party Leader poll, but his standing in our Cabinet League Table has scarcely changed.  Those who aren’t for him are against him, it seems.  This is not the best platform for a leadership bid.  And there is reason to believe that opinion on the Tory benches has turned against him since that Telegraph piece.  Some activists still cry “Bor-is, Bor-is”, but there are fewer of them.  The star of Jacob Rees-Mogg is rising in the east, sorry, south-west.  The blond beast is ageing.

Johnson aped Churchill today.  “But it is up to us now – in the traditional non-threatening, genial and self-deprecating way of the British – to let the lion roar,” he declared.  We know what the pitch to those MPs will be, just as we know what his game at this conference is, if a Conservative leadership election takes place in 2019, which is probable, or before, which is more than possible.  “Buy now!  Save your seats!  Just do it!  Only I, Sir Winston Johnson, with my tarnished but enduring appeal to voters, can get you re-elected!  Sweep the Mrs Chamberlains aside and go for Boris Churchill!”  It is a measure of this dazzling, selfish, generous-hearted, depressive, far-sighted, chronically disorganised Etonian outsider and heroic drittsekk that the appeal cannot be automatically dismissed.