Reports of the Labour party’s demise are greatly exaggerated. Despite endless hyperbole in recent weeks about its “existential crisis” and growing fears about left-wing entryism, the party is actually just living out the age-old pathology of its renewal cycle: Govern. Disappoint. Backlash. Strife. Modernisation. Govern.

Yes, the party is in a deep fug, but every Labour generation has undergone this process following a period in office because every Labour government has ended up disappointing its core supporters, to varying degrees. Even the sainted Attlee saw three members of his Cabinet quit over the imposition of NHS charges.

In short, there’s nothing new about Labour’s current predicament. Every period in government in the party’s history has been followed by a backlash and subsequent period of internecine strife. It happened in the 1930s after the disastrous experience in office between 1929 and 1931 and the subsequent McDonald split. The party didn’t govern again until 1945.

Then again, in the 1950s, the Bevanites and Gaitskellites tore into each other after the 1951 defeat. Thirteen years in the wilderness followed before Harold Wilson led the party back to power in 1964. While the legendary feuding in the 1980s almost destroyed the party, keeping it out of office for 18 long years.

Why does Labour experience this organisational self-harm after it loses power? Why does the Labour tribe always turn on each other with such venom? Perhaps the bar for success is set high for centre-left parties. If your politics is rooted in wanting to change the world and your leaders only manage to make it better, then that is, relatively speaking, failure.

And, so, the conflict between the party’s idealists and pragmatists has raged for a century. So despite the many shining achievements of the Blair-Brown years their record in easily shaded out by those who see only their shortcomings, (the flaw, perhaps, of Brown’s “redistribution by stealth?”)

As we’re now seeing in opinion polls and the share out of constituency party nominations for Labour’s next leader, there is a sizable chunk of the membership – or more precisely the activist base – that is decidedly more left-wing than the parliamentary party and largely discounts the most recent experience/ achievements of government. This is the backlash phase, with activists angry at the accommodations of the last Labour government and the inability of the party in opposition to oppose austerity more full-bloodedly.

Indeed, the generation of activists whose politics were shaped by the bitter recollections of those four election defeats during the 1980s and early 1990s seems to be giving way to a younger generation that has not yet earned the scars on its backs turning the party into a viable election winner.

You can see it in their Twitter user profiles, loudly proclaiming their adherence to socialism or feminism. It’s not enough to imply it; it has to be proudly stated. These Macbook revolutionaries eventually follow a well-worn path where youthful idealism is eventually tempered by personal ambition. Ask former CND member, Tony Blair.

So, right now, the party is essentially split, to paraphrase Robert Kennedy, between those who accept dealing with the world as it is and a new generation of fiery activists who look at the world as it could be and ask: “why not?”

Their rise is Ed Miliband’s legacy. His 35 per cent strategy was explicitly aimed at avoiding the hard choices around economy policy and welfare reform that created space for the fuzzy thinking of the “if-we-only-believe-hard-enough” crowd.

In Miliband’s defence, his calculations were driven by the need to keep the Labour family together. However, by failing to confront the ‘backlash’ and ‘strife’ phases following defeat in 2010, he simply postponed them. Hence, the current infighting.

The modernisation phase he left to his successor. But starting it is no straightforward task. If the process is rushed, a paralysing schism becomes inevitable. Kinnock knew that, as did the impatient Gaitskell. Push the party too hard too early and it will break. Previous leaders embarking on the modernisation phase were forced to fight one battle at a time in a drawn-out process of attrition. (Blair was fortunate in having the spade work done for him by Kinnock and Smith). So, by long and painful tradition, they relied on the inefficient and idiosyncratic use of multiple election defeats to give modernisation extra impetus.

In today’s party, this sees the pragmatists worry that the task of winning back middle-class voters in key marginal seats, who need reassuring that their big mortgage, two cars and foreign holidays will not be jeopardised by a Labour government expecting them to pay “a bit more tax,” will be fudged.

But any prospect of victory in 2020 has also got to see the party win back seats in Scotland too, where the SNP cleaned-up by campaigning to the left of Labour. It also needs to claw back those “left behind” voters in the North and Midlands who either stayed at home or switched to UKIP and who want a dose of the old religion. At the same time, it must please the urban modernists who see only positive effects from a fast-changing Britain.

Making sense of these mixed signals from the electorate provides a fillip for all sections of opinion within the party. Does Labour heed the call from Middle England for a return to Blairite pragmatism, or listen to the heartlands’ plea for a more familiar redistributionist agenda? Did Labour lose in 2015 because it was too left wing or because it was not left wing enough? No single narrative dominates the party’s thinking so modernisation needs to be pursued incrementally.

It’s all much easier for the Tories. The historian Andrew Roberts once remarked that an entire generation of Tory politicians were “emasculated” by their cataclysmic rout in 1945, when they lost 190 seats. Yet Sir Winston Churchill was returned as prime minister just six years later.

Perhaps, if your politics are mainly about preserving a set of beliefs, (or, in the Conservatives’ case, a social order) and modernity overruns that position, it is much easier to simply accept the new reality and move on, as the Tories did after 1945, accepting the Attlee government’s new settlement and contenting themselves to run it better than the socialists.

It’s probably harder for a centre-left party to move on so quickly. Labour people – from Corbyn to Kendall – didn’t come into politics to see people suffer and will always seek to mitigate their condition, to a greater or lesser degree. Supporting the government’s public spending cuts, at a time when so many people are in such need, does not come easy to anyone in the Labour family.

Ultimately, Labour will survive – as it always has done before. If it can come back from the Ground Zero of the SDP split and the 1983 general election annihilation, it can withstand anything. But this is not a quick process. The renewal cycle needs to be played out in full until a single dominant modernising story emerges that, however grudgingly, all sides accept.

The bad news is that this might not be the final leadership process until the party gets to that point.