“The worse it gets, the better,” Vladimir Lenin is once said to have remarked during the final days of Tsarist rule in Russia. Lenin believed that the greater the failures of Romanov regime, the bigger the dividend reaped by the Communists.

Today, two groups in the Labour party think something similar: that the darker the next half-decade is, the better for them. The first group are well represented by Jeremy Corbyn’s allies in Parliament and are, if not a majority, at least one of the loudest, groups among his supporters in the party membership. They believe that five more years of cuts, of growing wealth inequality, and a possible global recession will hand Labour victory in 2020, regardless of how far from the “political centre” the party is or is perceived to be.

The second group make up the bulk of Corbyn’s internal opponents, not just among the parliamentary party but among the minority of activists who are if not virulently opposed to Corbyn at least are sceptical about his prospects in a general election. They believe five more years of defeats – whether at local elections or following a cataclysmic rout in 2020 – will force the party membership to rethink.

The recent row over the publication of Margaret Beckett’s report in to the 2015 defeat is a case in point, a pointless post-mortem that told us nothing we didn’t already know.

Labour’s problem hasn’t changed. In 1960, after the party’s third successive defeat, Mark Abrams and Richard Rose wrote Must Labour Lose?, an autopsy of the party’s defeat which concluded that the party needed to add to its existing coalition of working class voters and socially-concerned middle class voters if it was to win again – it needed to speak to voters from the private sector, who were excited by the possibilities of Hire-Purchase and preferred ITV - which Labour had opposed the creation of – to the BBC.

In 1992, in Giles Radice’s Southern Discomfort, after the party’s fourth successive defeat, he concluded that Labour needed to add to its existing coalition of working class voters and socially-concerned middle class voters if it was to win again – it needed to speak to voters from the private sector, who had benefited from the Right to Buy.

Beckett’s report into the 2015 defeat, Learning the Lessons, found the party did well "amongst BAME communities, amongst liberal professionals, amongst younger people and amongst the most disadvantaged". Its coalition of the poor and the socially-conscious might be less white than the one that was too small to win in the 1950s and 1980s, but it is in all other respects identical. In short, Labour lost for the same reason it always does: it only secured the votes of people in poverty and people concerned about poverty.

A more useful set of questions than “why did Labour lose in 2015?” is: why did Andy Burnham lose in the leadership election? Why did Liz Kendall get under five per cent of the vote? Why has Labour’s 1997 landslide intake produced just one leadership campaign – the crushingly drab one of Yvette Cooper, that only kicked into gear when most of the ballots had been cast and Corbyn had already won?

As painful as it is for Labour’s centre-left, they won’t win a general election without securing the votes of the party’s left. A leadership candidate who cannot get the endorsement of Owen Jones will not get the chance to try to secure the support of the Sun. And just as five more years of cuts won’t be enough to turn it around for Jeremy Corbyn and John McDonnell in 2020, defeat at the general election won’t hand Labour back to the centre-left.

There are plenty of Corbynsceptic MPs and activists who get the scale of the problem. In the shadow cabinet, Heidi Alexander, Jon Ashworth and Chris Bryant are plugging away and attacking the Tories, while outside of it, Rachel Reeves, Shabana Mahmood, Liam Byrne, Emma Reynolds, Alison McGovern, Chuka Umunna, Jonny Reynolds are all coming up with new ideas for the party's centre-left. Liz Kendall herself acknowledged the problems with her own campaign today on the Daily Politics. But much of the party's centre-left is keener on rubbing the lessons from the general election in the faces of the left, rather than subjecting itself to a painful post-mortem following Corbyn's own landslide.