A movement that aspires to succeed has to begin by accepting that most people don’t think like it. It must obsess not over why people agree with it but why millions don’t.

It must focus its resources on seeking converts, not traitors. It must avoid becoming a subculture with its own language and rites, all of which are bemusing and alien to most people. It must spend every spare moment debating and discussing a strategy to victory, not confusing the enthusiasm of a minority for a plan to win. It must project an image of positivity, optimism and inclusivity, not of anger, bitterness and vengeance. It must make the average punter feel as though they could easily be part of the movement, without feeling they’ve signed up to a never-ending exam that other activists are always waiting for them to fail.

A party that wants to succeed must be determined to engage a public that simply does not share its passion

Jeremy Corbyn is going to win another landslide victory because of the movement behind him. More than two years ago Labour abolished the electoral college, replacing it with one member one vote and a supporters’ scheme so that anyone could join up and instantly have a vote. Ed Miliband’s leadership implemented these proposals at the behest of the party’s right. By moving towards US-style primaries, they believed, Labour would be freed from the grip of the trade union movement, and people sharing the right’s worldview would pour into the party, permanently shifting Labour’s political centre of gravity.

One snag: the Labour right lacked any compelling, coherent narrative to inspire anyone. People poured into the party all right, but their belief system could hardly have been more undesirable from the standpoint of the party’s right. In the recent US science-fiction drama, Stranger Things, children are snatched and dragged into the Upside Down, a parallel universe which is a dark, grim version of our own reality. Ever since it became clear that a little-known leftwing backbencher was heading towards a decisive victory in last year’s leadership election, his opponents have felt as though they have been dragged into the Upside Down.

Stranger Things: ‘Ever since it became clear that Corbyn was heading towards a decisive victory in last year’s leadership election, his opponents have felt as though they have been dragged into the world of the Upside Down.’ Photograph: Netflix

The movement behind Corbyn is not driven by Trotskyists, revolutionaries or even ideologues. What unites its foot soldiers is a rejection of a political consensus that they believe brought disaster in Iraq, financial collapse, unnecessary and ideologically driven cuts and policies that have disproportionately hammered the young. Many are strikingly aware of Corbyn’s flaws and limitations, but they fear his fall will lead to a restoration of the old order and the systematic removal of the left. Since Corbyn’s election, they feel that not only has their chosen leader been smeared by the press, but that they themselves have been subjected to campaign of vilification.

They believe MPs plotted to undermine their preferred leader before he was even elected, that they undermined him through his tenure in office and plunged the party into an unnecessary and destructive leadership contest at a time of national crisis. They are infuriated by bureaucratic manoeuvres they believe were designed to block Corbyn’s re-election, like an attempt to keep him off the ballot and a heavyhanded purge of the leader’s supporters.

The fury that has resulted may be understandable, but it will prove fatal if unchecked. The onslaught against the movement could yet destroy it, precisely because of the anger it has provoked. Talk of war and mass deselections will resonate with many Corbyn supporters and be affirmed with applause. Some may theatrically boo prominent members of the Labour family who oppose Corbyn. Hunts for witches and renegades, stirred up by pitchfork-holding Twitter accounts, may be instigated. That Britain is ruled by a Conservative administration that has shifted to David Cameron’s right, and that feels rather amused – almost pitiful – about Labour’s plight, will all be forgotten. Leftwing politics could be subsumed into a struggle against “the 172” – the number of MPs who voted no confidence in the leadership – rather than an attempt to dislodge Theresa May’s rampantly rightwing Tory government.

Voices calling for peace will not be popular, but they will be crucial to the success of Corbyn’s leadership and future of the movement that propelled him to victory. Labour MPs should accept the verdict of members of one of Europe’s biggest political parties. But everyone has to give. Talk of mandatory reselections should be abandoned. This will not force MPs into line but fuel a nihilistic sense among MPs of “I have nothing to lose.” Common ground should be emphasised.

In the 1980s there were far greater ideological differences between opposing sides. Today no one of any significance is calling for the nationalisation of the top 200 monopolies, for instance. Yes, Corbyn supports unilateral disarmament, but in the 80s it was a key article of faith for Labour’s left. From selection in education to the NHS to the economy and tax, there is actually striking agreement among MPs, members and unions. Owen Smith ran on a similar domestic platform to Corbyn, underscoring that unity. Issues that unite should be emphasised and built on, rather than differences emphasised for show.

If politics consumes a huge portion of your life – as it does mine – then it can be easy to forget just how little enthusiasm most people have about it. Coups, purges, Labour’s NEC, memes about the rival candidates pepper my social media timelines every day. Most people have spent the last three months slogging away at their job, going to the seaside, having after-work drinks, picking their kids up after school – getting on with their lives. Let’s be blunt. If members of the public are even paying attention to Labour’s car crash – and most have switched channel – “freakshow” is probably one of their kinder words.

The movement must now refocus all its attention on them. These are people who agree with them on many issues – higher taxes on the rich, publicly owned utilities, more workers’ rights – but also have often dramatically different attitudes when it comes to immigration and social security. A movement that wants to succeed must be restless in its determination to engage a public that simply does not share its passion.

Corbyn has posed by an olive tree to demonstrate his sincerity in reaching out. In doing so, he’s setting an example his followers must surely follow. The movement behind Corbyn brims with energy and has so much potential. It could spend the next few months stirred up by angry witch-finders while the Tories implement an agenda Margaret Thatcher would have balked at. Or it can focus on offering an inspiring alternative that is inclusive and relentlessly upbeat. That’s no guarantee of success. But the alternative is a guarantee of failure.