ALTHOUGH Tony Blair heaved the Labour Party back to the political centre—and electability—in the 1990s, he never entirely finished off its hard-left wing. It lived quietly on in pub corners, in parts of declining trade unions, among MPs on the party’s eccentric fringes; a mostly male, white and increasingly aged world slipping slowly into irrelevance.

At least, so Bagehot thought—until, one recent evening, he found himself in Camden Town Hall in London, at a rally in support of Jeremy Corbyn’s bid for the Labour leadership. There they were on the platform: the lefties from the public bar, those for whom no dog-eared old cause is too sentimental, no tax too high, no anti-American autocrat too distasteful. But where once there was a bored landlord wiping glasses, they now faced a fizzing throng of supporters. These booed Mr Blair’s name and roared their approval as a slightly stooped man, sporting a white beard, a crumpled shirt and a bemused expression, bustled up to the stage: Mr Corbyn, a political footnote suddenly turned headline.

Strange events are abroad in British politics. In May the Labour Party lost an election in which, under Ed Miliband, it was generally considered too far left of voters. In the race to replace him Mr Corbyn, a veteran socialist (and teetotaller), has outperformed his three opponents, and his own expectations, energising the party’s grass roots and inspiring thousands of new members to join up. He commands the support of more local branches than any of his rivals, the endorsements of the country’s two biggest trade unions and, polling suggests, a lead among Labour’s overall selectorate. His rallies are massively oversubscribed; the one in Camden so much so that Mr Corbyn had to address those waiting in the street outside from atop a fire engine.

How to explain Corbynmania? Labour’s messages, and with them its membership, tilted left during the Miliband years. The unions expanded their sway over the party. Meanwhile Blairites drifted away. Although it clashes with lessons of Labour’s election campaign, Mr Corbyn’s leadership bid has thus found a receptive audience. He has been lucky in his opponents, too. Liz Kendall, of Labour’s liberal right, lacks experience. Andy Burnham, of the soft left, is opportunistic and dreary. Yvette Cooper, in the middle, is credible but robotic. One Corbyn supporter, a don at Oxford University, claims it is as easy to sift the straight-talking Mr Corbyn from his rivals as it is a first-class student from his mediocre contemporaries on the first day of a new academic year.

At the rally in Camden, Bagehot could not help but see her point: the man knows his mind and speaks it. He proffered no direction-of-travel indicators, threatened to empower no communities of stakeholders and refrained from reconnecting with any hard-working families. But most striking was that the political credo he so straightforwardly expressed was utterly at odds with the fizz and optimism of the crowd (“Jez we can!” they chanted). For Mr Corbyn is a conservative.

Pessimism of the intellect

He does not look like one because his electoral strategy is bold to the point of fantasy. He and his supporters see British history not as a long process of mostly organic social and economic change, but as a succession of lurches forward propelled primarily by concerted vanguards of campaigners. Thus they are convinced that an electorate that just rejected a moderately left-wing programme in favour of a Conservative one can be induced to support a much more socialist platform. All Labour must do is shift the nation’s “Overton window”—the frame describing that which is politically mainstream and acceptable—leftwards through vim, organisation and assertion. They find inspiration in the example of Margaret Thatcher, insisting that her outspoken ideological confidence moved the British consensus to the free-market right (a reading that conveniently overlooks both the cannily compromising reality of her premiership and the vast socioeconomic shifts roiling 1980s Britain). In other words: they believe willpower can overcome political gravity.

This is radicalism, albeit of a myopic sort. But the wistful prospectus to which it is yoked is anything other. Mr Corbyn proposes to remove private providers from the National Health Service, return autonomous schools to local authority control, renationalise the railways, reinflate the welfare state and “reindustrialise” the economy. Parts of his speech could have been given at any time in the past half-century. “I was there in 1984 standing alongside the miners,” he recalled, “and judging by the appearance of some of you, you were there with me. Welcome back!” Corbynism, in short, is the choice not to create something new but to shore up an old status quo; of reinstatement over reinvention.

All of which gives his whole circus the air of a wasted opportunity. The MP for Islington North has the attention of many, including young voters otherwise disengaged from politics. These people, surely, deserve ideas responding to the convulsions—digitisation, automation, globalisation—through which they are living. Others on the left are thinking big about these. Roberto Unger, a Brazilian theorist, imagines a drastically less centralised and more experimental state. David Graeber, an anarchist, has interesting things to say about democracy and power in the age of the Occupy protests. Paul Mason, a British journalist, has just published a book on “postcapitalism”. Bagehot would not vote for the programme Mr Mason articulates, but admires him for grappling with trends like free information (think Wikipedia) and the “sharing economy” (think Airbnb), along with the explosion of data and networks that they symptomise.

Yet Labour’s supposedly radical man of the moment offers no such analysis. The defensive nostalgia of the grizzled blokes in the pub has consumed a movement that could have been forward-looking and original. Mr Corbyn is unelectable. Even less forgivably, he is boring.