Jeremy Corbyn, the left-wing Islington MP, has been elected to the leadership of the Labour Party in the first round of voting with 59.5 percent of the vote.

Just as remarkably, the hard Blairite candidate admired by the right-wing media, Liz Kendall, won a mere 4.5 percent. Labour now has its most left-wing leader since George Lansbury in the 1930s.

This is far better than anything we could have anticipated. In Corbyn’s first speech as leader, he hit all the left notes. He welcomed new members, as well as old members driven away by Blairism. He bashed the Tories’ anti-union laws, stood up for welfare, attacked the Murdoch empire, and defended refugees. His first act as leader was to join the pro-refugee march in central London, to a rapturous welcome.

For now, much of the response will consist of a fully justified guzzling of Blairite tears. All of the bullying and the moral blackmail and the condescension couldn’t hide their fear, and couldn’t dissuade a membership energized by a unique, unexpected opportunity, and sick to death of being spoken down to by the undemocratic, managerial rabble at the top of Labour.

This is the time to celebrate. This is our Oxi. Oxi to austerity, Oxi to Blairism, Oxi to managed politics, Oxi to a media that went into Project Fear mode the second Corbyn had a chance, Oxi to racism and the politicians who make it respectable, Oxi to the neoliberal consensus.

All of this was literally unthinkable only a few months ago. When Corbyn initially stood, he had no expectation of winning. The common sense at the top of the party was that voters had rejected Ed Miliband for being too left-wing. This was the consensus that the “Blue Labour” apparatchik Jon Cruddas attempted to reinforce with some bogus research a month ago.

Why, then, did Labour MPs even bother to endorse Corbyn and allow him onto the ballot? Because of the Scottish National Party, and the Greens. Because of the threat that Britain would have its Syriza, or its Podemos. Getting Corbyn onto the ballot was about demonstrating that Labour was still a broad church that could give a place to the Left.

As Paul Mason points out, they underestimated the anger and the underground radicalization of the grassroots. They also believed too much of their own bullshit about voters cleaving to the right. The major reason Ed Miliband lost in 2015 is because the largely young, working-class voters who said they would turn out for Labour, didn’t.

As far as they did turn out to vote, they voted Green or Plaid Cymru or SNP or one of the other alternative reformist parties. And they then turned out to the large anti-austerity protest earlier in the year.

It is often assumed by Marxists that capitalist crises are polarizing events. That is not always straightforwardly true. In the British context, the dominant reflex was to seek a reassuring center ground, to trust in a middle-of-the-road figure who would at least be relatively honest and fair in the handling of the crisis.

That was the basis for the brief, lamentable “Cleggasm” that propelled the Liberals into a coalition government. But soon, with austerity being expedited and deepened, polarization was more firmly in evidence, first with the student movement of 2010, then with a lurch to the right following the England riots in 2011.

There followed years of blight for the Left, punctuated by successive moral panics, and a rapid accumulation of votes and coverage by the racist formation, the UK Independence Party. Only now, eight years since the credit crunch, after the longest decline in living standards since the war, after years of benefit cuts for particularly the youngest, with more to come, has polarization resulted in an advantage for the Left.

This advantage depended on the Labour right underestimating their own inherent fragility, something that is both conjunctural (the wipeout in Scotland seriously weakened them) and structural (the traditional structures of political leadership are eroding in all the capitalist democracies). This fragility explains why a small chink in the armor of the Right was sufficient to allow Corbyn to be propelled to victory.

It isn’t that the Left is strong, it is that the Labour right is ideologically vacuous and historically pointless. There was a time when the Blairites seemed like a dynamic force in the Labour Party, and when some of their rhetoric about democratizing and reforming the party seemed to touch on real problems. Now they just seem arrogant and monotonous.

Anyone watching the debates between the leadership candidates would have seen just how uninspired, dismal, and insubstantial the Labour Party’s right wing has become.

One other factor is Corbyn himself, whose unique combination of virtues worked to his advantage in this election. He isn’t the most charismatic of speakers, but he is also charmingly free of ego. His understated manner inclines interviewers to underestimate him, but he has decades of experience as a parliamentarian, and that showed in his media appearances.

His decades of activism spell “unelectable” to the Westminster village, but it means he is adept at the kind of popular politics that the old party elites run by professionals and hired political mercenaries have given up on.

Now that Corbyn has won, however, the Blairite fightback has already begun. A raft of former frontbenchers have either resigned or made it clear that they will not be part of a Corbyn cabinet. Labour apparatchiks and pundits are wailing doom from their pulpits.

This is how Andy McSmith, a journalist close to the Labour hierarchy, explained their perspective:

Corbyn’s Labour critics have also been comparatively restrained so far. They say they have nothing against Jeremy personally, that he is a nice guy, and they object only to his politics. However, these are not £3 day trippers whose idea of political involvement is to log on, vote Corbyn, and tell your mates via Facebook: these are professionals who have invested their working lives in the Labour Party. They want to be in government again.

This is to say, the people who devised the system wherein people can register as “supporters” and have a vote in the election, now deride it and scoff those electors as mere clicktivists.

In truth, they are angry that these voters aren’t mere clicktivists. They don’t just vote, “like,” “retweet,” and “share.” Their online activities have fed into a nationwide campaign of mass meetings and agitation that, at times, resembled a social movement.

And that’s the problem: the “professionals” who have hijacked the Labour Party didn’t want active members, they wanted a passive membership base that would anchor Labour’s positions firmly to the right, acting as both cash cows and voting fodder for the machine. So their way of doing politics is threatened, and they’re going to fight bitterly to keep control.

Even with Corbyn’s overwhelming victory across all sections of the Labour Party, there is something incredibly fragile about the situation. Certainly, the strong result, and the dreadful vote for Kendall, means that there can be no immediate move to depose Corbyn. The party machinery will want stability and legitimacy in the process, not a chaotic post-election brawl. And it seems unlikely that with such a pitiful vote the Blairites will actually walk out — they would merely be jumping off the gangplank if they did.

The Blairites and their allies will wait. They will nurse their wounds and get their people in position and dig in for a time when they can act. So there is now a period of time, not very long, when Corbyn and his supporters can put themselves in position for the coming trench warfare, get their supporters nominated and voted onto party bodies, start drafting proposal for democratic change in the party, start preparing for the selection of parliamentary and local candidates.

Because there will be war in the Labour Party. Project Fear was just the panicked, clearly ineffectual start. And in that war, the right wing will have the backing of the media, the spooks, the civil service, and a good chunk of the membership.

Aside from the open combatants, there will also be another, more subtle line of attack. This will involve pressuring Corbyn to abandon his key commitments, one after the other, in search of a workable compromise, to the point where he drains away his popular support and is decisively weakened.

Of course, he will have to compromise on some aspects of his agenda, simply because he has to work with a parliamentary Labour Party that still reflects the balance of forces from a few years ago, and is thus overwhelmingly right-wing. But if he compromises on key issues such as Trident, he will lose supporters and he can give up on ever regaining support for Labour in Scotland. So, Corbyn’s Labour Party will be a battleground from day one.

Corbyn has said that his campaign is about turning the Labour Party into a social movement. That’s the only chance he and his supporters have. The era of tribal party loyalties, in which powerful bureaucracies were articulated with organized masses has been displaced. The social basis for Labourism, if it is to be revived, will be polyglot, and its supporters will be politically polyamorous. This is what Labour’s purgers failed to understand.

In the future, Labour’s supporters will have had a variety of political fealties in the immediate past, be it the Greens, or the nationalists, or the Trotskyists or some independent campaign. People work wherever it is useful to do so, and align with whoever it is helpful to work with. The concept of the party as an inclusive, ecumenical social movement, implies an awareness of that.

This would be the only possible counterweight to the entrenched, institutional power of the Right.