It is bewildering, isn't it, that Jeremy Corbyn's supporters still insist on supporting him?

Not only has the United Kingdom Labour Party leader suffered mass resignations from his shadow cabinet and a resounding vote of no confidence from his MPs, he has been comprehensively depicted as "unelectable".

What could be worse, for a party leader?

Corbyn, standing on an anti-austerity platform, took Labour's helm in a landslide leadership election victory last September.

At a time of political disengagement, he has inspired a surge in Labour's membership figures, so that it is now the largest party in Europe.

Really 'unelectable'?

But in the shocked, confused aftermath of Britain's June referendum vote to leave the EU, he now faces another leadership contest, triggered by rebel Labour MPs who have rallied behind a "unity" challenger, Owen Smith.

The trouble for Smith and his backers is that Corbyn looks set to win - again. But if, as many media commentators insist, Corbyn is unelectable and an incompetent leader to boot, why would Labour members continue to support him?

Do his supporters want Labour to lose elections, thus consigning the UK to endless, punishing years of Conservative Party rule?

Are they refusing to clock Corbyn's terrible poll ratings, more interested in the purity of politics than having Labour in power, or even just halfway effective in opposition?

For the resurgent left across Europe and in the United States, these will be familiar charges.

Attempts to reach voters from a supposedly 'electable' and yet increasingly distant centre that sticks to triangulation, spin and neoliberalism, have yet to grasp that politics has shifted, that something has broken, that there has been an erosion of trust in what this centre represents.

The self-proclaimed socialist Bernie Sanders, who persuaded Hillary Clinton to adopt some of his progressive platform policies when he dropped out of the Democratic leadership race last month, was routinely dismissed as unelectable - it was a big theme, for months, during the leadership race.

Ditto Greece's anti-austerity party, Syriza, led by Alexis Tsipras - now in government, but previously portrayed by that country's media as unrealistic and inexperienced.

Regardless of respective electoral fortunes, this revived left has met with the same flavour of derision along the way.

No more centre

Partly, such disparagement is a straightforward underestimation of the appeal, the hopeful pull of genuinely progressive politics for people facing acute economic hardship and serially let down by the traditional left - which in reality has moved ever-rightwards.

Across Europe, established centre-left parties are viewed as not just failing to alleviate financial devastation, injustice and inequality, but actively administering policies that made things worse.

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This is why, in a social landscape ruptured by the 2008 economic crash and the cruel austerity measures that followed, politicians capable of mobilising support aren't the ones coming from the middle ground - this cohort has lost credibility.

Attempts to reach voters from a supposedly "electable" and yet increasingly distant centre that sticks to triangulation, spin and neoliberalism, have yet to grasp that politics has shifted, that something has broken, that there has been an erosion of trust in what this centre represents.

In the UK this should have been one of the takeaways of the EU referendum - in part an anti-establishment protest vote - but centrism still yearns for its own significance.

A different type of politics

Meanwhile, leftists - the unelectable, the incompetent, the naive - have gained support by talking about participatory politics, and with policies geared towards ending austerity, tackling inequality, introducing fairer taxation, free education and bolstering the welfare state.

This doesn't mean that masses of people have suddenly swung towards socialism - or even that they need to, for the left to gain power.

It does mean, as Marina Prentoulis, senior lecturer in media and politics at the University of Anglia, puts it, that people "are demanding a different type of politics and no longer want to leave it to experts in suits, who think about electability but not about the electorate".

Similarly, if endeavours to cut down a resurgent left aren't cutting through, this may be because the operational premise from which such assessments are made is no longer deemed valid.

That's a significant break, because media and political classes have for so long codified the characteristics of leadership - and so convincingly that such narrowly prescribed qualities are understood to be self-evident prerequisites for those seeking power.

Meanwhile, in the UK at least, one additional factor potentially derailing attempts to discredit Corbyn could be pure overkill.

Analysing newspaper coverage of Corbyn during his first two months as Labour leader, a report from the London School of Economics found it to be overwhelmingly hostile- with researchers stating they were "astonished by the systematic way in which Corbyn is being actively delegitimised by the media".

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So it's possible that such relentless attacks have served to expose the wiring behind the curtain, the distance between the commentators and the commented-upon.

As Salon magazine's Bill Curry, writing about the US media's underestimation of Bernie Sanders a few months ago, noted: "It's hard to report on a peasant revolt from inside the castle."

Concerting more support

Far from persuading Corbyn's supporters to peel away, the media's mocking of him may instead have rallied more around him.

When the Labour Party changed voting rules for its forthcoming leadership election, disenfranchising more than 100,000 new members, more than 180,000 people signed up as Labour supporters (with voting rights) within an allocated two-day period.

One British newspaper broke this down as people signing up to the party at "the remarkable rate of one a second" - netting the party some $5.9m in fees.

Labour now has some 600,000 members and supporters, who can potentially mobilise to campaign, canvas and win votes - precisely the action now required to grow support beyond the grassroots and into communities.

It's an unprecedented opportunity for the left in Britain - but you can expect it to be met with plenty more derision and bewilderment.

Rachel Shabi is a journalist and author of Not the Enemy: Israel's Jews from Arab Lands.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.