How do you explain the Boris Johnson phenomenon? Is it the mainstream media’s fault or should we lay the blame on the people? On this, the eve of his anointment as leader of the Conservative party and therefore as British prime minister, it is fitting to ask why the unbelievable has become a reality.

His sins, both political and personal, were recorded in detail in last week’s Guardian. Together they painted a portrait of a man who should never have come close to inhabiting No 10 Downing Street. But the blathering, bumbling bluffer will be there all the same.

Let’s consider first the way in which the majority of national newspaper editors urged Tory MPs to vote for him. Foremost among them was, of course, the Daily Telegraph, which has spent years acting as his enthusiastic cheerleader, earning its Daily Boris nickname without an apparent blush. A leading article two weeks ago gushed: “Mr Johnson is Mr Brexit” and “a man our readership knows very well.”

It reminded them that, “in 1989, this newspaper sent a 24-year-old Boris Johnson to Brussels as a correspondent, and readers were able to follow his progress as he grew bemused, frustrated and exasperated with an EU bureaucracy hell-bent on wrapping Britain in red tape. Finally, he concluded that the UK was better off out”. It did not remind them that his despatches from Brussels were, at best, laced with half-truths and, at worst, purveyed downright lies.

The Sun, hysterically anti-EU since the 1980s, was an unsurprising, unashamed Johnson supporter. Its most recent editorials pointed to “BoJo’s upbeat optimism” and to the supposed “BoJo feelgood factor”, arguing that it “is infectious and will be music to the ears of workers struggling after years of austerity and belt-tightening”.

After hosting a debate between Johnson and Jeremy Hunt, it reported that 75% of its readers plumped for Johnson. Proof once again that the Sun marches in tandem with its readership.

Facebook Twitter Pinterest The Telegraph has been an enthusiastic cheerleader for Johnson. Photograph: ClipShare

The Daily Mail was also stimulated by Johnson’s optimism and charisma. “He radiates energy,” it trilled. “He positively fizzes with ideas, promising to propel the country to new heights of prosperity, inventiveness and social cohesion … Atomic Boris has the potential to power up a Britain weary of Brexit and the crippling uncertainty it has caused.”

It dismissed “charges of populist rightwing intolerance” as being “hopelessly wide of the mark”.

Although the Daily Express toned down its pro-Brexit propaganda after its former owner, Richard Desmond, sold it to the Daily Mirror publisher, Reach, it gave Johnson its backing. It praised his (alleged) “tremendous record as mayor of London on law and order” and opted for his (dubious) “vision for a free, post-Brexit Britain”.

The Times was more cautious but, ultimately, called on the Tory membership to give Johnson their votes despite his “weaknesses”. In acknowledging that “there are legitimate questions about this honesty, loyalty and personal relationships”, it conceded “he was not a good foreign secretary” due to “his lack of attention to detail and tendency to speak carelessly”. On the plus side, “he is a Brexiteer” and, as such, “may be the only person who could convince his hardline colleagues to accept the compromises needed to secure an orderly EU exit”.

The Sunday Times, more eurosceptic than its daily stablemate, thought Johnson’s “tendency to bluster and not answer questions may be one he shares with many politicians but he has taken the art form to new levels”. Even so, in accepting that Johnson is not a man for details, the paper was seemingly happy that “the broad brush is his domain” and encouraged him to “take his lead not from Mr Trump, another stranger to detail, but an earlier US president, Ronald Reagan”.

So far then, so predictable. The bulk of the press, despite some serious misgivings about his political nous and his wayward personality, were willing to give Johnson the nod. But it would be something of a stretch to imagine that the sympathetic newspaper coverage is the reason for his popularity among the Tory party faithful and also among a swathe of the less politically committed middle and working classes who rarely, if ever, vote Conservative.

What gives Johnson the edge is that Trumpian Reaganite quality of being a politician who pretends he is not. This is more complex than it appears because the pretence is both unconscious and conscious. His bumbling act is an extension of his personality and is therefore authentic. Yet, at the same time, he tends to accentuate it because, over time, he has become aware of the favourable public response to his shtick.

Like a veteran comic, he understands how to work his audience. Their approval gives him the confidence to dissimulate. Never was this more obvious than during his BBC TV interrogation by Andrew Neil. Although Neil referred continually to the fact that Johnson was avoiding the question by going off at a tangent, it did not deter Johnson from employing the tactic. It comes naturally to him.

Facebook Twitter Pinterest Andrew Neil and Boris Johnson on BBC TV’s The Andrew Neil Interviews. Photograph: Reuters

It was one of the most fascinating half hours of television, with Neil, a master of political and economic detail, growing increasingly frustrated at being unable to pin Johnson down. He chose to play the role of a schoolboy who, in spite of not knowing the answers to the teacher’s questions, sought to compensate by deploying a mixture of bluff and bombast. Neil didn’t buy it.

At one point, Johnson accused Neil of embodying “BBC-generated gloom and negativity”, a ridiculous assertion because Neil is anything but a creature of the corporation he just happens to work for.

But Johnson’s aim was not to please his interviewer. He was selling himself to viewers and was aware of the value of scoring the odd debating point, even one that was way off target.

Doubtless, viewers’ reactions were split. Johnson survived well enough to delight his supporters and dissembled enough to confirm the scepticism of his detractors. What it confirmed for everyone, however, is that Johnson’s success is based not on his intellect but on his being a personality, a performer rather than a politician, who is known universally by his first name.

Less clear is whether the media are responsible for creating “Boris” as a celebrity.

Just how did a buffoonish joker find a way to overcome all the negative aspects of his persona in order to connect to the public and end up as prime minister? It is tempting to offer a one-word answer to the mystery: Brexit.