For me, Brexit fell from the sky. On the night of 23 June last year, while the referendum count was in progress, I was flying home from an Observer job in New York. When we took off from JFK the pilot, in his measured British Airways tones, mentioned that several people had been asking him the latest from the polls. “It’s close,” the pilot announced, “but the BBC are reporting that Mr Farage is saying ‘Remain will edge it’.”

Six flying hours later, when the plane had bumped to a halt at Heathrow and we were stretching economy-class limbs, the pilot piped up again. He went through his regular spiel about the weather on the ground and then he delivered his punchline. “For those who have been wondering about the referendum,” he said, “contrary to what we thought last night, it is a narrow victory for Leave.”

Rarely have I experienced that cliche of a collective intake of breath, but this was one occasion. There was silence in the cabin, broken only, from up front, by a couple of muted cheers. Queuing blearily in Arrivals, it was as if the pieces of the place you lived had gone into a Wizard of Oz whirlwind and settled in a new configuration. I sat on the train home and flicked through online reports. At one point I caught the eye of the guy opposite me who was doing the same. He looked up and mouthed the sentiment that had been running through my head since landing. “Fucking hell,” he said.

For some of us, half of us, I guess that mouthed expletive has never gone away over the past year. A few times, in Sliding Doors fashion, I’ve wondered how things would have looked if on landing the BA pilot had given the expected punchline. We would now be ending the second year of a Cameron government, no doubt exercised by NHS crises and Labour infighting. There would be little talk of Scottish independence. Perhaps, in the absence of the anarchic first domino of Brexit, Hillary Clinton would be in the White House. And news bulletins would not be filled from here to eternity with armchair psychology about Jean-Claude Juncker and Donald Tusk.

The prospect of mass immigration, long one of the paper’s predictable drumbeats, was for a month the only story in town

Looking back, I’ve no idea why I was surprised. I had spent some time following Nigel Farage around and watched his affable private manner harden into something much more cynical when he whipped up packed town hall meetings with talk of Dale Farm and Syrian refugees. I’d witnessed the “democratic deficit” in action at the European parliament, tried to reconcile the tone of that debate with British sentiment, and come up laughably short. And I’d spent the period leading up to the referendum not only often travelling the country but also religiously reading the Daily Mail, the paper that appeared, not for the first time, to be dictating and amplifying the public mood.

May and June of last year was one of those times when news seemed to take on a narrative life of its own. The only parallel I could think of was in those last febrile weeks of Princess Diana’s life, when the frenzy of the tabloid press seemed to make a shocking ending inevitable and necessary. My colleague Carole Cadwalladr has indefatigably unearthed the ways that social media became a toxic tool of the Leave campaign. That effort only reinforced what was happening in plain sight, however. Rarely has there been a moment in British political life when newspapers – and, in particular, a single powerful newspaper – focused the thinking of its readers so effectively on one question. As Mark Twain observed, “There are laws to protect the freedom of the press’s speech, but none that are worth anything to protect the people from the press.”

As we face another weird polling day that hardens surreality into fact, I’ve been reading through the front pages and editorials of the Daily Mail over the course of the last year, in sequence, as if they were a novel, or a blueprint for the nation we have become. It has not been a joyful experience. I began with the starting pistol to the referendum, and ended with “Crush the saboteurs” and wondered exactly how we had got here, and where we are heading next.

Chapter one of that story takes us back to last February and the critical moment when David Cameron returned from his negotiation with the EU ministers to present his gamble to the public. He came back from Brussels with predictably few new concessions but with a sense, reinforced by his gilded passage through political life, that he could charm both his cabinet and the Tory press on to his side.

In hindsight that was a catastrophic miscalculation. The first inkling of this came on the morning of 2 February when the Mail pre-empted his announcement in a front page that asked: “Is that it then, Mr Cameron?” before going on to suggest that “Cameron and Brussels stitched together a deal designed to keep us in the EU…” That piece was written by the Mail’s then political editor, James Slack. It emerged subsequently that Cameron invited Paul Dacre, the Mail’s editor, to a meeting later that day to discuss ways in which the paper might be persuaded, pointedly, to “cut him some slack” on his EU deal.

24 June, 2016: shocked traders on the Frankfurt stock exchange the day after the EU referendum, with the Daily Mail front page on a screen behind. Photograph: Alamy

The following day the Mail threw the Prime Minister’s request back in his face by devoting its front page to “The great delusion!” beside a close-up of Cameron looking as untrustworthy as the more regular inhabitants of that space, Sir Shifty and Tony Blair. To hammer home the point the following day, the Mail took the unusual step of running its leader comment as a splash on page one. The question asked was “Who will speak for England?” referring to a parliamentary heckle once used against Neville Chamberlain, which helped end both appeasement and his career. The Mail left us in no doubt who the contemporary Chamberlain was. “As in 1939 we are at a crossroads in our island history,” the paper trumpeted (leaving aside the fact that at the previous crossroads, its own editorials stood sympathetic to fascism and acted as a recruiting sergeant for Oswald Mosley. “Hurrah for the Blackshirts!”).

In its new declaration of war on the government the paper railed at how debate was being suppressed. “Eurosceptic MPs have been muzzled – banned from speaking on the most momentous issue of our time…” (a contention that clearly proved false). It then sought to answer the question in its headline, sorting through the alternatives to Cameron. Having trashed the character of Boris and the careerism of Gove, the editorial ended with what appeared to be a whisper in the ear of the then home secretary, a quiet memorandum of understanding. “How disappointing that Theresa May, who spoke so powerfully against mass immigration last year, appears to have been bought off … With a tsunami of migrants flooding across Europe, can such tinkering with the small print really be enough to silence her reservations?” Keep your head down, Theresa, it seemed to say, and all this can be yours.

The following month the hostility between Paul Dacre’s paper and the Cameron government only increased. According to a subsequent Newsnight investigation there had been another meeting after those front pages, this one between Cameron and the Mail proprietor, Lord Rothermere. In that meeting it was suggested, and not denied by the peer, that Cameron made a case for replacing the Mail’s editor on grounds that he was threatening the nation’s future with his stance on Brexit. Whether true or not, that was the story that reportedly reached the famously volatile Dacre and left him “incandescent” – now not only determined to push harder for Brexit, but also to unseat Cameron.

It is fair to say that Paul Dacre had never had much time for what he christened Cameron’s “chumocracy”. In the course of his 25-year editorship of the Mail Dacre has always let his newspaper do his talking for him, and there is an omerta among Mail staff, loyal and fearful in equal measure. The most vivid portrait of the country’s most influential newspaperman comes in the recent book by Adrian Addison, Mail Men, the final third of which offers unprecedented insight into Dacre’s methods and character through the eyes of often anonymous former colleagues. The timing of the book means that it covers little of events surrounding the referendum, but it is essential reading now to begin to explain them.

It is a truism that over time newspapers take on the character of their editor, particularly editors as dictatorial as Dacre. Addison presents a portrait of his Oedipal instincts; Dacre was nurtured by his stellar predecessor Sir David English, before eventually eclipsing him. English was urbane, effervescent, clubbable; Dacre was not. He made up for his social awkwardness with a Stakhanovite work ethic that has seen him spend 15-hour days in the Mail’s Kensington offices for nearly four decades, a devotion to duty now rewarded with a salary of around £1.5m.

In one of the few interviews Dacre has ever given, to Sue Lawley on Desert Island Discs more than a decade ago, he described himself as “a hard bastard who leads from the front”. Each weekday evening between about seven and 10pm he leaves his office to sit on the paper’s back bench and remorselessly rehash that day’s offering, all the while delivering what staff call “the vagina monologues”, heated critical assessments of his journalist’s efforts, with scattershot use of his favourite word, “cunt”. Though the Mail’s website, with its sidebar of celebrity shame, is the most visited news site in the world, Dacre has little interest in technology. He edits with a blunt pencil, often apparently with enough vitriol to shred his page proofs.

The rage he reserves for a story missed is nothing to that he directs toward the hated liberal establishment. The roots of that anger are harder to fathom, and not really explained in Addison’s book. Dacre was by no means an outsider to the perceived “liberal elite” he has determined to destroy. His father, Peter, was the New York and showbusiness corrrespondent of perhaps the most successful newspaper this country has ever known, John Junor’s Sunday Express, which at its height was selling 5m copies (Peter Dacre also wrote songs for Bing Crosby). Dacre was awarded an 11+ state scholarship to a private school in liberal Hampstead (he is remembered by schoolmates “mostly for being able to balance a tennis ball on his foot”). After editing school and university newspapers, his first job was at the Daily Express in Manchester.

Lord Rothermere in his Kensington office. Photograph: The Independent/Rex/Shutterstock

His own success at the Mail has bought him schooling for his two sons at Eton, membership of the Garrick, a chauffeur, a house in the country, flat in town and a shooting estate in Scotland (generously subsidised by the EU). He rarely rubs up against the people he believes he represents. “It always amused me that his shoe leather never wore out,” one reporter told Addison, “because every day he was on a carpet in the office; he strode out the door and was in a car which deposited him either at home or a restaurant. He would be horrified at what modern Britain had become – but he was never part of it.”

Despite this insulation, Dacre has always presented himself as having a unique “feel for the emotions of ordinary people”. He still apparently locates this feeling in the 1950s London suburb of Arnos Grove in which he grew up, and which persists as the model of the Mail’s middle England. When Dacre got his first editor’s job, at the London Evening Standard at 42, he went back to Arnos Grove as if he were John Major with his gnomes. “It had worked. I got there,” he recalled, mistily.

Reading through those Mail front pages and editorials from last year, you can’t help feeling that all of Dacre’s accumulated “suburban” outrage at the ways of the British “metropolitan establishment” came to a head over the spring and summer. Cameron’s call for his sacking coincided with a unique uncertainty in Dacre’s own long tenure at the paper. From the time that Rothermere had inherited the paper from his late father, Vere Harmsworth, there have been murmurs that the young owner was out of political step with some of Dacre’s hardline political stances, particularly over Europe, but that he pursued the family policy of non-interference because Dacre’s paper made him so much money. In the first years of his editorship Dacre took the circulation of the Mail to an unprecedented 2.5m. No newspaper has been immune to the challenges of the internet, however, and in May last year, a month before the referendum, with circulation of the Daily Mail at around 1.5m, Rothermere was forced to offer a profits warning to the City for the first time. The share price fell nearly 10%, and in interviews Rothermere talked openly of the website and not the printed paper as representing the company’s future.

Did those bad numbers and the rumours of Cameron’s interference create an even more ferocious intent in Dacre’s editorial pencil, a more determined display of power? It is hard to believe they had no effect. The profit warning came on 24 May. The headline of that morning’s paper reads: “Knives out for Cameron: dozens of Tories threaten no-confidence vote over PM’s ‘shabby’ Brexit scaremongering” and tell PM to “set a date for his departure”. Dacre was not going anywhere quietly.

What followed in the next month reads like an object lesson in how a newspaper, trusted implicitly by its readers, can exert its influence. Dacre is a seasoned enough newspaperman never to launch a campaign that he knew he could not win, and in May last year, despite what the polls were saying, he clearly scented something in the air. Circumstances had presented him with various gifts: there was an opposition leader who didn’t have the wit to sing the national anthem at a Battle of Britain memorial service. The Liberal Democrats were dead in the water. Ukip was on a roll. The first record Dacre chose on his Desert Island Discs was Oscar Peterson’s Night Train, because its relentless rhythm expressed his idea of daily newspaper production. The Mail’s front pages have long had that familiar rhythm – NHS, political scandal, foreign aid waste, quangos, health tourism, terrorist threats – but from the beginning of June that rhythm was interrupted by a single strident note.

The world the mythical Daily Mail reader inhabits, the world that lives pretty comfortably in the shires and hankers for monocultural 1950s Arnos Grove, is always depicted in its pages as being under threat. Only rarely does the paper go down the route of all-out scaremongering, however. But this was one occasion. For several weeks the paper had been railing, with some justification, about the government’s “Project Fear” tactic. In late May Dacre seemed determined to show Cameron exactly what fear was all about.

The prospect of mass immigration, which had long been one of the paper’s predictable drumbeats, was for a month the only story in town. Looking back at those front pages there is no mention of £350m for the NHS, little attention to judicial sovereignty, not even the light relief of Geldof and Farage and their flotilla. The only issue becomes the deepest fear of the island race: invasion.

Read in sequence, those front pages have something of the shape of the opening pages of Great Expectations. First there is a series of front pages about Britain’s “wide-open borders”. These stories are sparked by a coastguard’s interception of a boat of 18 Albanian asylum seekers off the coast at Dymchurch. It follows with the splash that the boat had been bought on eBay. The following day, by implication, we get an extrapolation of what this boat portends. The headline identifies “EU killers and rapists we’ve failed to deport” and details, in the manner of Trump and Mexico, that “thousands of violent thugs and rapists from the EU are walking Britain’s streets”, a number “equivalent to a small town” flooding in through Kent. The following week, we have our first view of Magwitch himself, Avni Metra, 54, who is surprised at his flat in Borehamwood in the proximity of a kitchen knife, and apparently wanted for murder two decades ago in Tirana. He is not alone: there is also the “one-legged Albanian double killer” Saliman Barci in Northolt. Though Albania and Kosovo (where the killers claim to come from) are not members of the EU, and it is not clear how leaving will do anything to prevent their arrival in Britain, the implication is clear. Cameron and his remainers are bringing a townful of knife-wielding Albanian murderers to the home counties. The 2,500 reader comments under this story speak with one voice: “Get them out now and get us out now!”

Paul Dacre edited the London Evening Standard 1991/1992. Photograph: Daily Mail

Of the 23 weekdays before the referendum, the Mail led with this immigration narrative on 17 of them. One exception was the grim morning of 17 June when Jo Cox’s murder made the front page. Her killer, Thomas Mair, was not a one-legged Albanian. Mair was, of course, a violently extreme advocate of “Britain first”. The Mail appeared anxious to relegate his shouted rage against the perceived evils of multicultural Britain to a side-issue, however. He was, their report emphasised, just a “loner with a history of mental illness”. The following day it reported that the police were investigating primarily not Mair’s far-right links in the targeting of Jo Cox for her pro-immigration views, but failures in the social services that led to his depression going untreated. (The Mail subsequently, in November, shamefully, reported news of Mair’s conviction for the only murder of a sitting MP this century on page 29 of the paper, making the case that his motivation appeared to be that “he feared losing his council house to an immigrant family”).

Like the politicians, after this salutary event, the paper took a couple of days off from its own version of Project Fear, but by the Tuesday before the referendum it was back at the drums. It seems telling, in retrospect, that in none of these stories was blame laid at the door of the home secretary, in whose remit immigration and asylum fell, and on whose six-year watch the town full of EU rapists and murderers had continued to receive its benefits. It was the fault of the EU and the chumocracy; it was “Cameron’s migration deception” and his plot to “let 1.5m Turks into Britain”.

Given the timing of the count, the moment of Brexit triumph is not properly examined in the print edition of the paper until 24 June: “Take a bow, Britain!” The editorial borrows a favourite phrase of Nigel Farage and talks of the day the “real people” rose up against the arrogant political class. It was, however, a day for these “real people” to start building bridges, with their “out-of-touch” fellow citizens. This bridge building lasted only the weekend. Having railed against the ways in which government had sought to gag “Eurosceptic” voices in the campaign, the paper now led the charge to silence all dissent against the referendum result: “Now a plot to block Brexit” is Monday’s headline, introducing the language of the “enemy within” to characterise political debate.

Before the Mail turns the full force of its anger on those it quickly christens “Remoaners”, however, there is the chance to shape the answer to the original hypothetical question of three months earlier: “Who will speak for Britain?” Again, a retrospective reading of the paper’s front page narrative seems to reveal its mind at work. As Addison’s book notes, Dacre, who arrived at the Mail in 1979, ceded to no man in his admiration of Margaret Thatcher. His former boss Sir David English did much to shape her image, but he was never a Eurosceptic and used to argue passionately with Thatcher about her stance toward Brussels. Dacre, by contrast, was with her all the way. Having watched his star columnist Sarah Vine do her unsuccessful Lady Macbeth audition on behalf of her husband, Michael Gove, Dacre asked another loaded question on the front page of 7 July: “Who’ll be the new Maggie?” In the choice between May and Andrea Leadsom, there was no choice.

The resultant reporting of the coronation of the prime minister will make interesting reading for future historians. In her first speeches and exchanges May seemed at pains to strike a consensual, inclusive, rational note in the difficult times ahead. The Mail, which had argued her to power, was from the beginning having none of that. Reading its front pages now, you see how they are marshalled to invent her as a leader of apparently unrestrained ferocity toward her opponents. The slightly nervy vicar’s daughter was to become Boudicca. For the first month of her tenure there was not a mention of May without a kind of Bring Up the Bodies menace. She was warlike: three times in August alone, the Mail had her and her Brexit army “on the march” in headlines. She was responsible for “savage blood letting” and all sorts of “first blood”; by September she was pictured telling “top brass to stop hounding our soldiers”. She never appeared in the Mail’s pages without some kind of attendant threat. An editorial celebrated her “steel toe-capped determination to carry out the will of the people”. Her rise was contrasted on the 13 September with a front page that Dacre appears to have long imagined, but clearly relished: “The crushing of David Cameron.”

James Slack, the Mail’s former political editor who became Theresa May’s official spokesperson earlier this year. Photograph: Steve Back / Barcroft Images

In October, May (by now “the lady not for turning” mark II) invited Dacre for a private dinner, her only social meeting with the editor of a newspaper in the first six months of office. His thank you note appeared to come in a series of splashes, which celebrated her determination to “savage the liberal elite”. Whatever May’s private thoughts about consensus, the champion the Mail required was a leader who according to an editorial of 12 October would “damn the unpatriotic Bremoaners and their plot to subvert the will of the British people”. These fifth columnists were over the course of these months an ever growing band that included not only obvious suspects like Blair and Nick Clegg and Ed Miliband, but also the likes of Amal Clooney, JK Rowling and Emma Thompson (“luvvies who lecture us on migrants as they jet between mansions”), the “pro-Brussels CBI business group”, the Church of England, Nicky Morgan (“Miss U-Turn”), Lord Heseltine, the BBC and of course “a well-heeled group of London intellectuals used to having things their own way”. The following month, two new hate figures emerged: first Gina Miller, (just about everything Dacre’s Mail hates in one simple package: an bolshie, foreign-born, intellectual mother and former banker championing representative democracy) and of course, in a headline that set a new low in press standards, the “Enemies of the people” that were high court judges.

In all these months, if you read only the Mail, that idea of “people” against whom all these unpatriotic forces were ranged appears to get narrower and narrower. They are essentially and always, “people like us”. One of the most telling insights in Andrew Addison’s book answers the question of how almost everyone in the Mail’s feature pages tends to look the same.

A former editor on the paper’s Femail section who goes under the pseudonym “Penny” told the author: “[All the women] have to look good in a wrap dress and be a certain size. Every story – with the very occasional exception – has to adhere to this template. So that, no matter how good the story is, if the person doesn’t look like they might be a Daily Mail reader – it’s never going to work. The makeup artist and hair – they’re enormous budgets – are being sent every day, several times a day, to several stories, you know, ‘ju-jing’ people up. And that ethos, for sure, stems from Paul Dacre; this story will only be meaningful if he thinks it [affects] ‘someone like us’.”

It must have seemed a gift to Dacre that the prime minister of his choosing fitted that Femail template so convincingly. Theresa May might have shown the “steel of the new iron lady” when she triggered article 50 in the new year, but she was also the kind of Femail the dominant Mail most admired: “Never mind Brexit – who won Legs-it?” it asked of its people about May’s “pins” in March.

By this point, by the time the negotiations had begun, and just before the election was called, a year that seemed to have been dictated from a Daily Mail script had found a predictable ending. James Slack, the paper’s political editor, who had been at Dacre’s right hand as he constructed his narrative – beginning last February with the challenge to Cameron, and in the vanguard of the coverage of immigration and the routing of the Bremoaners – was imported to the prime minister’s team as official spokesman, her very own Alastair Campbell.

If anything, perhaps not surprisingly, the rhetoric from Downing Street going into the general election now sounds almost indistinguishable from the Daily Mail editorials that preceded it. There would be a “triple lock on Brexit to stop obstruction by diehard Remoaners”. May would characterise herself as a “bloody difficult woman” in facing up to the EU. Meanwhile, the Crushing of Cameron prefigured the “Crushing of the saboteurs” (You have to admire at least the attention to detail in this headline, Dacre finding an imported French word to characterise his enemy.) The “illiberal elite” is on the march.

Observation suggests that as people age, they tend to become more like themselves. Dacre is 68. If the past year is anything to go by, he and his paper seem to be becoming more Dacre-like with each passing month. He first took the helm of the Mail during the ERM crisis in 1992. At the time, Vere Harmsworth, then proprietor of the paper, told the Financial Times: “I am quite clearly in favour of a common market but I am not in favour of a federal Europe. Nor is the Daily Mail.” He added that perhaps his new editor did not share that distinction and occasionally went too far. “Sometimes I think Paul would like to tow England out into the middle of the Atlantic,” he observed. Twenty-five years on, the moorings are being released, and Dacre appears ready to set sail.