Labour’s conference began as farce, but culminated in a triumphant affirmation of the most radical incarnation of Corbynism yet. The abortive attempt to remove the party’s deputy leader, Tom Watson, enraged Jeremy Corbyn so much he broke with his near-cardinal aversion to swearing, and threatened to destabilise Labour’s last major pre-election opportunity to showcase its radical vision. The supreme court’s damning ruling against the prime minister reinvigorated morale and offered a necessary reminder of the frightening political stakes at hand, but it was a democratic insurgency at the conference – although sometimes colliding with old-style machine politics – that re-energised a Labour grassroots preparing to march into an existential political battle.

Rather than policies cooked up by unelected advisers and thinktank wonks, the wisdom of members would be trusted instead

The promise of Corbynism was of a member-led, democratised party; and while this commitment has much to recommend it, it has always had limits. For example, the party leadership and major unions have resisted moves towards a key membership demand – open selection for MPs – because this would require MPs to automatically stand in a contest with other candidates if they wish to be reselected. As a result, not a single MP has been deselected, leaving the politics of most of the parliamentary party at odds with the membership. Cynical manoeuvres reminiscent of the New Labour era have sometimes been deployed too: for example, the leadership successfully forced free movement off the agenda at the last two conferences, fearing the potential unpopularity of such a commitment. For those who fear the Labour machine can capture even the most radical of leaders, the latter is the most striking example. Labour members elected its most pro-migrant leader ever, who celebrated his first leadership triumph by speaking at a refugees’ rights protest – and yet the party has shown a depressing failure to make the case for freedom of movement since.

The tussle over Brexit also exposes the limits of the party’s venerated democratic culture. When the party’s national executive committee hammered out a statement committing to a referendum with remain on the ballot – as People’s Vote campaigners have noisily demanded – but with Labour taking a neutral stance, there was no proper discussion. Instead, its members were asked to vote on it by email. A conference vote on whether to back remain was treated as a loyalty test – with the Momentum leader, Jon Lansman, telling members to vote with their hearts – although hysterical claims that tactics reminiscent of China’s totalitarian regime were used were wildly off the mark: as one pro-remain campaigner told me, it’s hardly surprising that after four years of Corbyn’s leadership most elected local delegates will be passionately loyalist. “We did remarkably well, considering,” he says.

Play Video 9:46 Owen Jones at the Labour conference: make or break for Corbynism – video

But it is the democratic uprising on policy that reminded members why they have invested so much of their lives into what can broadly be called the Corbyn project. It is unlikely that commitments such as net zero emissions by 2030, support for freedom of movement – which did get a hearing this time – and the closure of all detention centres would have been offered by the leadership. These are demands that emerged from the membership. What always enthused those most committed to the project is that rather than policies simply cooked up by unelected advisers and thinktank wonks, the wisdom and imagination of members would be trusted instead. That process can be fraught. The compositing process (which hammers out the wording of policies put to conference) for the Green New Deal sometimes descended into rancour. Some trade union officials tried to dilute the motion, and an angry exchange was provoked when one climate activist showed a lack of empathy for unions wanting to protect their members’ jobs. But a democracy that is not messy is not truly a democracy at all.

Will Labour’s democratic transformation last? Many of Corbyn’s lieutenants are haunted by the insecurity of their political project. They are all too aware of the level of opposition within the parliamentary party, and they know that there is no obvious successor to the leader. They fear that if the right took back the party political vengeance would be devastating, from a full-scale purge to the shutting down of the party’s democratic structures in order to stop the left reviving ever again. Indeed, as one senior Labour figure promised when Corbyn became leader, the retribution “will have to be brutal, putting the left in a box for 30 years or out of [the] party”.

What is striking, however, is that political pundits rarely suggest Labour’s electoral prospects are threatened by the excessive radicalism of its political prospectus: the 2017 election, in which the party’s unapologetically leftist domestic agenda proved critical to securing 40% of the vote, ended that argument. Instead, the media consensus is that Labour’s fortunes are at risk because of excessive triangulation – centrism, even – over Brexit.

Like it or not, Boris Johnson still has two paths to election victory | Simon Jenkins Read more

That the Brexit culture war has drowned out Labour’s transformative agenda – and crowded out a narrative of the many versus the few in favour of remain versus leave – has certainly depressed the party’s grassroots. But the reason delegates left the conference far more enthused than when they arrived is because, rather than being bogged down in discussions over customs unions and access to the single market, they were debating issues that had drawn them to politics in the first place: austerity, housing, workers’ rights, poverty, the climate emergency. Corbyn’s own truncated leader’s speech received rapturous applause precisely because it recaptured the magic of 2017, promising to end a four-decade-old free market consensus, with policies from taxing the rich to public ownership.

Both the Tories and Lib Dems hope that an election framed entirely around Brexit will starve Labour’s domestic agenda of oxygen. If Labour can force a hearing for a radical agenda crafted in part by its own membership, however, triumph is possible. A four-year attempt to decisively break Labour from the UK’s failed neoliberal consensus has been turbulent, painful and sometimes chaotic. A new society has already been born in the imaginations of Labour’s activist base. And some who have waited a generation or more dare to dream it is finally within reach.

• Owen Jones is a Guardian columnist