Could 2019 finally be Boris Johnson’s year? It is a testimony to the former foreign secretary’s staying power that one can even ask this question. By any rational measure it should by now be possible to dismiss the clown prince of conservatism as one of those political adventurers whose charisma gave them a sight of the summit, but whose constitution was not cut out for the ascent.

Lightweight, narcissistic and apparently unenthused by the hard work of governing, Mr Johnson looks like a man who has been found out. And yet, remarkably, it is still too early to write him off. He may deserve to be dismissed but, in a field of stolid political performers, Mr Johnson cannot be discounted. He seems simply more vivid than the monochrome alternatives. Through opportunism, wit and sheer refusal to be marginalised, he enters the new year still in contention for the top job in British politics. Indeed, if it is ever to happen for him, it will almost certainly have to be in the next 12 months.

Most Tory MPs assume that Theresa May will be replaced as prime minister in the coming year, although this is not a given. The odds favour a change not least because 2019 is likely to bring the next stage of the Brexit negotiations — the one that will determine the future relationship with the EU — and there are too many MPs who do not wish to entrust this to Mrs May. This is Mr Johnson’s opportunity.

Once every non-Conservative’s favourite Tory, Mr Johnson has fallen low among his former metropolitan admirers. The decision to champion Brexit cost him dearly among liberal-minded Conservatives. His shambolic and aborted leadership 2016 campaign alone ought to have been the end of his ambitions.

His period as foreign secretary was characterised by an inability to be serious and a seemingly dilettante approach to detail. He showed himself too addicted to the blustering buffoonery which delighted his domestic audience but baffled and irritated the rest of the world. Even at home, his Clarksonite humour has begun to pall. Dithering over Mrs May’s approach to Brexit, he was finally shamed into resigning by the more speedy departure of David Davis, the Brexit secretary. Resuming his newspaper columns and speaking from the backbenches he was vituperative and fulminating, but always afraid to strike.

It was as if it suited him not to have to take responsibility for the final shape of Brexit. Instead of owning the event he had done so much to bring about, he has preferred to complain that his Brexit has been betrayed.

There is also the nature of the leadership contest to consider. Under the rules, Tory MPs whittle a list of candidates down to two, who are then presented to the party membership. Since it is commonly held that Mr Johnson would win the wider ballot, his opponents have an incentive to stop him before then. Almost every Tory leadership contest in recent memory has been characterised by a campaign to bring down the frontrunner and it is remarkable how often this succeeds. Many MPs believe they need a fresher face. Other, younger Brexiters have emerged to challenge his claim to the purist mantle of leadership. In a crowded contest, the difference between elimination or advance could be a margin of eight to 10 votes.

Yet there are some partisan arguments for Mr Johnson. He stands above his rivals in public recognition, exuding an optimism and cheer which many crave. The Conservative vote is overwhelmingly pro-Brexit now so Mr Johnson would be aligned with his electors. Those who voted Leave do not want to be told they are wrong; they want to be proved right. He is the man to tell them they were.

The fate of the Conservative party is totally aligned with Brexit. The next leader needs to deliver on other issues — especially public services — but he or she will be judged on Brexit, and so must try to make a virtue of it. There is no doubt Mr Johnson’s championship of Brexit has made him a hate figure among Remainers but, in an increasingly polarised politics, that may be less of a problem than it once was. The game may be about solidifying the Tory vote.

More important than all that is one crude calculation: the next election will be extremely hard for the Tories to win. They need to gain seats to govern alone in a country that is crying out for change, for investment in public services, for a reason to believe things are going to get better. If Labour leader Jeremy Corbyn is the only change on the menu, then he will win. The Tories need a new story and that can only be one of national renewal after Brexit. (Of course that does mean avoiding a calamitous economic collapse but he has that May woman working on preventing that for him.)

In any case, Mr Johnson is ideology-light. He may be elected as a Brexiter but his first move will be to tack to the centre and try to repair links with his party’s liberal Remainers — hence the stories of his reaching out to Amber Rudd, the liberal-minded work and pensions secretary, with an offer of deputy leadership on a joint ticket.

When Tory MPs vote, they will have two primary thoughts: who is most aligned to my views and who is going to save my seat. If Mr Johnson is deemed by many to be the answer to the latter question (and he is) then he is more than in with a shout.

This is not to predict a Johnson premiership, merely to observe that it is foolish to assume it cannot happen. This is a defining year for Mr Johnson. By force of personality and opportunism, he has kept himself in the game. He has lost stronger hands than the one he now holds. But he is still at the table.

robert.shrimsley@ft.com