A visit to one of the US socialist’s rallies inspired former Labour strategist Steve Howell. In an exclusive extract from his new book, he writes about the power of storytelling and the eureka moment behind the party’s 2017 campaign slogan

As Jeremy Corbyn was campaigning to be Labour leader for the first time in 2015, something unprecedented was happening in the US: a democratic socialist was emerging as a serious contender for the presidency. Never in US political history had someone labelling themselves with the “S” word been more than a fringe candidate.

Hillary Clinton had name recognition, huge resources, and the backing of the entire Democrat establishment. However, she had alienated many grassroots Democrat supporters with her backing for regime-change wars and trade deals that had decimated entire industries and destroyed thousands of jobs.

Bernie Sanders, on the other hand, had voted against the invasion of Iraq in 2003, and was challenging her with a campaign platform that – like Corbyn’s – zeroed-in on growing wealth inequality. Sanders reiterated that core message in rally after rally through the summer and autumn of 2015. And it soon became clear he was striking a chord with voters.

By 2016 I wanted to see what it was like to #FeelTheBern. And I was not disappointed. The rally I attended – on 4 June, on the concourse of the Los Angeles Coliseum – was slickly organised. Staff and volunteers managed security as more than 13,000 people queued patiently to pass through the barriers. There were three hours of music and speeches by Hollywood A-listers – among them Rosario Dawson, Shailene Woodley, Max Carver and, my own favourite, 90-year-old Dick Van Dyke “giving a young politician a hand-up” by leading a “we love you, Bernie” sing-along. By the time Sanders made his entrance, the event was all over Twitter and the anticipation was huge. Flanked by his wife, Jane, and his children and grandchildren, he spoke from a lectern decorated with a US flag and the campaign’s “a future to believe in” strapline, and stuck to a text that embodied the arguments he had been repeating at every single rally for months. There was no message-creep and no need for him to shout – every word would be of broadcast quality for mainstream media and live streaming online.

Afterwards I was not alone among Corbyn’s supporters in reflecting on what Labour could learn from the Sanders campaign. Not only was there considerable common ground on policy, they were both “anti-establishment” politicians who had the authenticity and credibility, on the one hand, to counter the rightwing populism of Donald Trump and Nigel Farage and, on the other, to inspire and mobilise young people on a scale not seen for a generation.

Facebook Twitter Pinterest Jeremy Corbyn campaign rally, Buchanan Street, Glasgow, 7 June 2017. Photograph: Jeff J Mitchell/Getty Images

However, importing ideas from another country, even one with a nominally common language, is a hazardous business. Some ideas do not travel well. Sometimes good ideas are dismissed because of where they have come from.

When Bill Clinton emerged to win the 1992 presidential election, the Labour modernisers fell in love with American politics. They saw Clinton’s “new” Democrats, with their focus on appealing to middle-class aspiration, as the model for New Labour. The one thing they expressly did not acquire from Clinton was his liking for campaign rallies. Bill is a charming and engaging orator who loves a big crowd, but New Labour had a strong aversion to political rallies, dismissing them as preaching to the converted. Which is all very well if the media is on your side, but for politicians challenging the status quo, every opportunity to speak to large numbers of people directly is like gold dust.

Sanders had made a virtue of necessity in building his campaign around big rallies that were welcoming to people new to politics. Looking back on it afterwards, he wrote: “A rally of thousands of people standing together … is something unforgettable and extraordinarily powerful. It is not something that a television ad can accomplish.”

The rallies were a generator that powered all the other elements, creating virtuous circles of highly charged activity. Videos would be shared far and wide on social media. New volunteers signed up at rallies would be trained to go out canvassing. Contact details collected would be used to disseminate campaign materials and raise money online.

Mass fundraising from small donors was one of the stand-out features of the Sanders campaign. At the outset, he had decided that “you cannot take on the establishment if you take their money.” Sanders was also adept at using social media, despite personally being a novice.

But he was not dismissive of conventional methods. He had used paid-for radio, television and print advertising in numerous previous election campaigns and believed it still played an important role. In his bid for the presidency, as his support grew, he was able to compete with Clinton on paid advertising. By the end, the Sanders campaign had spent more than $100m on media buying. What distinguished his use of a conventional medium, however, was the way his ads – in both their imagery and words – were mainly about people and their stories. While the Clinton campaign was running traditional candidate messages, focusing on her political record, the Sanders ads were – as marketing agency executives put it – “tapping into what people are feeling” and offering “a deeper sense of idealism”.

Facebook Twitter Pinterest Both ‘anti-establishment’ politicians with the authenticity and credibility to counter rightwing populism ... Bernie Sanders and Jeremy Corbyn. Composite: Sean Simmers/PennLive.com via AP/Matt Cardy/Getty Images/AP/Getty

At Westminster, as the end of March 2017 approached, the inspiring Sanders rally I had gone to felt very distant. The local elections were looming. Campaign materials had to be produced within a matter of days, and our plans to get a policy bandwagon rolling had been delayed by the horrific Westminster Bridge attack. In the discussions with Southside, Labour’s head office near Victoria, during that period, there was much rolling of eyes when I offered some thoughts on how we should campaign in the local elections. I had half-expected my references to the Sanders campaign to be dismissed, and they were (“he lost,” I was told), but I had not bargained for the amusement use of the phrase “narrative arcs” would cause.

Storytelling has been used in marketing communications for years, simply because it is how most of us talk to each other most of the time – we tell people about things that have happened to us or others and then we might discuss what we feel or think about them. Conversation is mainly storytelling. And so is the best political communication, which is why some of the Sanders videos were so effective, and why the leader of the opposition’s office – known by the acronym Loto – had already accepted a kind offer from the film director Ken Loach to use his skills.

But this goes wider than how you produce a video. The whole campaign needed to tell the same story – an overarching narrative that voiced people’s fears, frustrations and hopes, and described a road to a better future. In a dishonest way, the big personalities of neo-liberalism, Ronald Reagan and Margaret Thatcher, were ahead of the curve on this. Their narrative triumphed for a generation because they convinced enough people that public spending and trade unions were to blame for the economic woes that hit capitalism in the 1970s, and that the private sector, set free to operate in de-regulated global markets, would create wealth and affluence.

But, if I was ever frustrated by some of those early discussions, one thing that would always lift my spirits was the irrepressible activity of what were known in Loto as “Jeremy’s outriders”. There were dozens of them on Twitter and Facebook who, day in and day out, were pumping out great material exposing the Tories and putting across many of our arguments. I include in this organised groups such as JeremyCorbyn4PM and Momentum, but mostly they were people acting on their own initiative out of sheer personal commitment. When the election was called a month or so later, they would play a crucial role. The Tories had nothing like it. Since the election, they had produced a “digital toolkit”, but Peter Stefanovic – a lawyer who had given up his day job to spend a year campaigning, and one of the outriders I had most contact with – thought it lacked a crucial ingredient: “The difference is that we believe passionately in what we’re doing, in the manifesto, in the principles behind it and how it’s going to change the country. You can’t manufacture that belief.”

Facebook Twitter Pinterest On message ... a Sanders rally at Santa Monica High School football field in California, on 23 May, 2016. Photograph: Ringo Chiu/AFP/Getty Images

Stefanovic is a natural communicator with a knack for finding the right words to make a point or, dare I say it, tell a story. If this was easy, more people would be good at it. But language is a complicated thing. And the Sanders campaign was not so helpful in this respect. Some of their terms could be imported – a “rigged” system was one we used – but George Bernard Shaw was right when he said the US and Britain are two countries disunited by a common language. Corbyn could not say he would “stand up for Main Street against Wall Street” and “fight for the shrinking middle class” without confusing everyone.

Among British political terms, I felt the phrase “left behind” presented some problems. In a note to Seumas Milne, the director of strategy and communications, before I started as his deputy in the leader’s office, I said I thought it was divisive. Ukip and far-right newspapers such as the Daily Express were using “left behind” to pit predominantly white working-class communities against a so-called liberal metropolitan elite. In using “left behind” we were actually reinforcing the false idea that the only people left behind are in Brexit-leaning areas where traditional industries have been decimated. Who is most “left behind”: a young person in Islwyn who can’t get a job, or a young person in Islington who can’t afford the rent on a bedsitter, never mind buy their own home? Globalisation destroys jobs in some parts of the country and inflates house prices in others. “Left behind” pits its victims against each other. Which, of course, is why Farage and co use it.

Milne and I were agreed on this, and he had already started discussing these narrative issues with two consultants, Marc Lopatin and Jem Bendell. In a blog a few months earlier, they had argued that Theresa May had “put her tanks on Labour’s lawn” by kicking off her premiership with “a spot of cross-dressing” in her pitch to ordinary working-class families. To respond, Labour needed to create a “permission space” with voters who weren’t listening to us because the Tories had been successful in blaming us for the deficit. Arguing that tactics and language had to be “fit for purpose,” they had said: “And that purpose is securing votes. So, while Corbyn’s ultimate vision involves stirring a lost spirit of solidarity and community, Labour must embrace voters as they find them and design conversations accordingly. Because the prize is bigger than reconnecting with former Labour heartlands. When Mrs May references working-class families as ‘just getting by,’ she also knows that millions of families higher up the income ladder identify themselves in the very same terms.

“So, when Labour speaks, it needs to explain how government has been failing families across the board and how this can be fixed ... If Jeremy Corbyn’s leadership can lift its gaze beyond the food bank, the government will have a fight on its hands.”

I did not see austerity as only being about food banks – or its other extreme manifestations, such as homelessness – but was that the impression we were giving?

Facebook Twitter Pinterest Flying the Momentum banner ... groups such as Momentum and JeremyCorbyn4PM along with the individuals of ‘Jeremy’s Outriders’ played a crucial role. Photograph: Daniel Leal-Olivas/AFP/Getty Images

Jon Trickett, meanwhile, had prepared a paper for the Loto strategy group that overlapped with these discussions. Trickett is one of Corbyn’s closest allies and brings to the table not only the insights of an MP from a northern seat – Hemsworth in West Yorkshire – but also a searching political mind that looks beyond what’s going on in the trenches. Trickett’s paper emphasised the need for Labour to create “a majoritarian coalition” around a “transformational” offer rather than use “retail” politics to appeal to different interest groups. When a general election came, we should make it about the kind of country we wanted to build and why it would serve the interests of the great majority of people, not only those experiencing the most acute symptoms of Tory policies.

This analysis tallied with my own view that, however the Tories dressed it up, using terms like the “just about managing” or the “big society”, we had to show that they always act first and foremost in the interests of a tiny elite. This applies on so many fronts. While a pay cap for everyone working in the public sector had hit the living standards of millions, the Tories were giving away billions in tax cuts for big business and the richest 1%. While corporate lawyers were on the fat cat gravy train in the City, the Tories were attacking funding for members of the same profession who preferred to represent people mistreated or injured at work. Even small business owners, the backbone of local Conservative parties, were ignored on an issue like late payment if it meant challenging the big businesses whose cash flows are boosted by it.

In time, Lopatin and Bendell would propose replacing “left behind” with “held back”. “Held back” could be applied to a whole range of ways in which most people’s lives are limited by a society run for the rich. We saw it as majoritarian and unifying – it spoke to both sides of the Brexit divide. More than that, it implies a call to action: whereas “left behind” encourages people to think of themselves as victims, “held back” suggests an obstacle to be removed. It prompts questions: what is holding me back, why and how can I do something about it? There was a story emerging here – and, like the best stories, a contradiction that required resolution. Looking back on it, we were all inching towards an approach that would gel around “for the many, not the few” – a suggestion that did not surface until the first full day of the general election campaign.

The pressure on Milne and me to make a decision was intense because leaflets were going to print and artwork was needed for the campaign bus. That afternoon, Labour’s national executive committee (NEC) was due to gather for a scheduled meeting and would expect our presentation to answer this most basic of questions. The strapline we had used for the local elections – “standing up for you” – was designed to position candidates as champions of their communities, but it was not applicable to a campaign aiming to win power at Westminster and deliver fundamental change. The idea of people being “held back” was already built into our narrative, as was juxtaposing “a society rigged for the rich” against “one in which people could lead richer lives”. But the two campaign co-ordinators, Ian Lavery and Andrew Gwynne, were still deeply unhappy about any use of “rich” or “richer”, which had been misinterpreted by some of the participants when tested at focus groups, and almost everything else we toyed with seemed lame and unoriginal.

As I pressed on with writing the presentation for the NEC, Milne went to see Gwynne and Lavery to listen to their concerns and discuss other options. The meeting was inconclusive, but Gwynne came back to Loto to continue the brainstorm with Milne by running through past Labour straplines and discussing which ones had worked and which hadn’t. They agreed the 2005 motto “Britain forward, not back” was the worst they could remember, with the 2015 effort “better plan for a better future” not very far behind.

As they delved deeper into the past, the words “the many, not the few” from the party’s constitution came up. The phrase was part of a new version of clause IV proposed by Tony Blair and adopted at a special conference in 1995 to replace Labour’s longstanding commitment to “common ownership of the means of production, distribution and exchange”. The dropping of the old clause IV was opposed by those of us who saw it as a New Labour move to distance the party from the idea of public ownership. However, the new clause contained phrases that are common ground for all its members, among them the words adapted from Shelley’s poem Masque of Anarchy. It was written in 1819 following the Peterloo massacre at St Peter’s Field, Manchester, when cavalry charged into a crowd of tens of thousands who were demanding the right to vote. For Milne, it felt right to use them again in a different context, and Gwynne agreed.

By now it was nearly midday, and my NEC presentation still had a big hole in it. When I scurried into Milne’s room, he said: “What do you think of ‘for the many, not the few’?” It was one of those FFS moments when you realise there’s a good reason why some things stand the test of time – in this case, nearly 200 years. With the word “for” added, the phrase encapsulated the idea of building a society that serves the great majority and not accepting one that is run by and for a privileged elite. It went beyond modifying the way the country is run by making it “fairer” or “better” and implied a transformation to a wholly different way of doing things.

Of course, the fact that Blair had used the words complicated this interpretation. Would some people consider it sullied? How could the same slogan apply to a “centrist” platform – whose proponents were “intensely relaxed about people getting filthy rich” – as well as our much more radical one? We hardly had any time to debate these doubts, but would the vast majority of voters know or care about them anyway? My instinct was that most people would not be aware of how “the many, not the few” had been used before and those who did would realise Corbyn – of all people – truly meant the message it embodied.

• Extracted from Game Changer: Eight Weeks that Transformed British Politics, published by Accent Press on 18 April (£15.99). To order a copy for £13.59 go to guardianbookshop.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99