In the wake of the Labour Party's defeat in Britain's general election on May 7 - its worst in nearly three decades - a contest is under way to select a new leader. But without an honest analysis of that defeat, there is a risk that the party's choice will merely pave the way to a similar disappointment in 2020.
The difference between now and the 1980s is that Labour then was on an upward trend following a near-death experience. This time, we are headed downward from an unprecedented series of three election victories under Mr Tony Blair, starting in 1997.
We did not lose because Labour is an egalitarian party. Britain, for all its class traits, believes in social justice. We are an inclusive society and want to see everyone get a fair start in life. We don't expect people to end up equal, but we see it as the job of our politicians to lean against inequality.
It was the strength of Mr Ed Miliband, the departing Labour leader, that he not only reflected this preference for fairness but also spotted something else: Since the global financial crisis, the public's intolerance for inequality has turned into outright anger about the polarisation of incomes between the very rich and the rest.
But Mr Miliband's attempt to use this as a weapon against the incumbent Conservatives met with limited success. Picking up on a popular view of the Tory leadership as a "posh boys' club", he set out to mobilise working-class and middle-class voters against the rich and powerful in society, linking their privileges to his political opponents. The Conservatives, of course, use mirror-image tactics to appeal to higher-income groups against welfare recipients and those they regard as the undeserving poor.
So there was a race to see whose rhetoric would attract the most votes, which the Conservatives won. Why? Partly because the rest of us do not pay for rich people's wealth (except when they cheat on their taxes), whereas general taxpayers do fund Britain's generous welfare system and sometimes feel that the unemployed are not just workless but work-shy.
The bigger reason Labour lost the argument is that the British, on the whole, do not like income disparities being turned into class war. Earlier in his leadership, Mr Miliband fought on a platform of social justice and fairness, using the language of "one nation". In the campaign, he seemed intent on pitting one half of the nation against the other.
It did not help that Mr Miliband himself is a well-off north Londoner, educated at Oxford and Harvard, someone with no first-hand experience of the lives of the people he was championing. It was not the essence of the inequality argument that people rejected so much as its articulation. His ideological crusade seemed unconvincing.
There was another hurdle in his way, one that Mr Miliband never addressed adequately: What would a government he led actually do to remedy inequality?
He argued for the need to "change the way the economy works" and whom it works for. This found an echo in public opinion: Many feel that business has become less a means of generating wealth, fairly distributed, than a vehicle for personal enrichment, especially for some extraordinarily well-paid beneficiaries in the financial sector. Mr Miliband's proposal was to pile taxes on the rich, but this is not the same as making the needy better off or rewarding aspirational voters.
In the absence of any realistic programme to reform the economy in a redistributive way, Labour fell back on a series of expensive financial offers to the public: capped energy prices and rail fares, controlled housing rents, a government-backed "living wage" and reduced tuition fees. Though welcome to many, these sounded implausible or unaffordable in straitened fiscal times.
This perception meshed with Labour's reputation - largely, but not entirely, unmerited - for losing control of government finances when in office before 2010. Tory strategists hammered home the message that Labour's policies would bring chaos. Unfortunately, Mr Miliband had failed to establish his fiscal credentials earlier; by the time of the election campaign, it was too late.
So what are the lessons from Labour's electoral meltdown?
For a start, a party committed to radical change has to be careful in balancing its message. It needs to construct a case for change, not rely on sound bites. The "haves" in society are prepared to make sacrifices for the have-nots, but they need to be treated to a reasoned argument, not a "them and us" assault that undermines rather than builds consensus.
While people admire Labour and its commitment to social justice, they won't sign up for what looks like an ideological vendetta, particularly if they fear becoming undeserving financial casualties of it. Voters are justly cautious.
There is no reason to believe they will always reject a leader to the left of Mr Blair, but they do not regard business, big or small, as the enemy - much as they would prefer to see business earnings properly tied to performance. If a political leader goes in for leftist rhetoric, they want it backed by a practical programme. Otherwise, the message appears unhitched from reality.
In this election, the number of people undecided late in the race was greater than usual. I do not accept the idea that the pollsters were wrong because they simply underestimated so-called shy Tory voters. British elections are won in the centre ground inhabited by a good 15 per cent of the population who do not necessarily lean left or right. Those people want to be convinced of a party's leadership, economic competence and sense of fair play.
If a party aims its policies at only one section of the electorate, this will not be sufficient for victory. You have to be able to draw voters from the centre to your side, especially in a campaign's final days.
This was a huge problem for Labour when it became clear that in order to govern, it would have to rely on parliamentary support from a resurgent Scottish National Party, predicted to win almost all the constituencies north of the border. Labour suffered from too much uncertainty about its programme, and its leader's credibility, to withstand fears among English voters of Scottish nationalist influence.
The leadership contenders all fault Labour's strategy under Mr Miliband. They rightly talk about reconnecting with voters, but when they also talk about the need for party unity, this sounds like continuity and an unwillingness to make hard policy choices. This is a luxury that is not open to them - not if they want to win.
NEW YORK TIMES
The writer, a former Labour Party campaign director, was a Cabinet minister under prime ministers Tony Blair and Gordon Brown.