In 1964, Lyndon Johnson told the US Congress: “This administration today, here and now, declares unconditional war on poverty in America.” Fifty years later, Ed Miliband is set to declare his own war - on inequality. More than ever, the Labour leader is convinced that the widening chasm between the rich and the rest (revealed again today  by Oxfam) is the defining issue of our time.
In the years before the crash, inequality was dismissed as a left-wing talking point, redolent of the “politics of envy” and inimical to middle class “aspiration”. Incomes might have been rising faster at the top than at the bottom but all, it was thought, were sharing in the fruits of seemingly permanent growth. Tony Blair captured the spirit of the age when he declared that he didn’t go into politics “to make sure that David Beckham earns less money”. But the financial crisis and the uneven nature of the recovery that has followed mean that, as Miliband declared in his Hugo Young Lecture  last month , “tackling inequality is the new centre ground of politics”.
When he made the issue a defining theme of his Labour leadership campaign in 2010, it was viewed as a radical challenge to the Westminster consensus. But three and a half years later, Miliband can pray in aid an impressive array of political and intellectual figures. In the US, where 95 per cent of the rise in national income between 2009 and 2012 was captured by the top 1 per cent, Barack Obama has spoken repeatedly of the need to narrow the gap between the rich and the poor (a departure from the bland US emphasis on widening “opportunity”) and radical Democrat Bill de Blasio won a landslide victory in the New York mayoral election after vowing to address “the crisis of income inequality”. For Miliband and his strategists, such figures are crucial evidence of his claim that the tide is flowing in the left's direction.
Over the same period, Pope Francis has warned that “inequality is the root of social ills”; Conservatives such as Jesse Norman, David Skelton, Robert Halfon and Sarah Wollaston have urged their party to reject libertarian individualism in favour of a Burkean commitment to social justice; and the World Economic Forum and the IMF have identified inequality as one of the greatest threats to future prosperity. From supposedly being a left-wing obsession, the income gap has become a political obsession.
Miliband, more than most, can claim to have been ahead of the curve. Since rising to political prominence, he has consistently argued that progressive governments have both a moral and an economic duty to limit inequality. As he wrote in a piece  for the New Statesman on The Spirit Level in August 2010, "We, politicians and the public, have to decide what kind of society we want to live in, and whether the difficult task of greater equality is worth the candle. It is - and it is at the very heart of why we need to move on from New Labour. During our years in power, we didn't do enough to stop the gap between rich and poor getting wider. If you really believe in a society where there is social mobility, where we look after each other, where we build social solidarity, then the gap matters."
He is now increasingly convinced not just of the moral and economic case for tackling inequality but also of the political case for doing so. If it was once thought that parties couldn’t afford to talk about the gap for fear of alienating aspirational centrists, Miliband believes that they can’t afford not to. Polls show that as many as 80 per cent of voters believe the government has a duty to reduce inequality, while measures designed to do so attract overwhelming support. As I’ve noted before , if Miliband is a “socialist”, so are most of the public. Around two-thirds of voters support a 50p tax rate, a mansion tax, stronger workers’ rights, a compulsory living wage and the renationalisation of the railways and the privatised utilities (putting them to the left of the Labour leader).
The political success of his emphasis on the “cost-of-living” (regarded by Labour strategists as a “proxy” for inequality) is due in large part to his recognition that this is a recovery “for the few, not the many”. While avoiding appearing to deny that growth has returned, he can complain at how unfairly its fruits have been distributed. Britain today is a country in which, for the first time ever, there are more people from working families living in poverty (6.7 million) than from workless and retired ones (6.3 million). When Miliband delivers his response to George Osborne's Budget on Wednesday, it is these failures that he will target.
The traditional political objection to progressive taxation was that it would repel the middle class voters who dreamt of one day joining the ranks of the rich. But even were this once true, few now entertain such ambitions after years of falling wages. The living standards crisis, with 11 million low and middle income workers seeing no rise in their earnings since 2003, has created the potential for a cross-class coalition of the 99 per cent against the 1 per cent (who now account for more than 14 per cent of all income).
Miliband will vow to address inequality through a combination of redistribution - the 50p tax rate, a mansion tax, a bank bonus tax, a major crackdown on tax avoidance (a subject which I'm told he will soon address in detail), the repeal of the bedroom tax, a less punitive benefit cap - and predistribution (seeking to create more equal outcomes before the government collects taxes and pays out benefits) - universal childcare, a mass housebuilding programme, the energy price freeze, a higher minimum wage, greater use of the living wage and worker representation on remuneration committees.
The long-term question for Miliband, if he wins office, and for all British progressives is how much of a difference all of this would make. In his new book Capital in the 21st Century  (recently highlighted  by Miliband strategist Stewart Wood), economist Thomas Piketty warns that, contrary to mainstream left and right assumptions, widening inequality is an innate feature of modern capitalism (one temporarily masked by the atypical post-war period) and will be only be curbed through a global wealth tax. On a domestic level, he argues , top rates of income tax should return to their pre-neoliberal levels of 70-80 per cent.
But if there is little prospect of Labour's election manifesto making room for such policies (and many economists reject Piketty's pessimistic assumptions), it is clear that Miliband will still offer the most comprehensive programme for tackling inequality of any political leader for a generation.
There was once a time when David Cameron was prepared to acknowledge the gap between the rich and poor and its baleful effects. In his 2009 Hugo Young Memorial Lecture  he noted:
Research by Richard Wilkson and Katie Pickett has shown that among the richest countries, it's the more unequal ones that do worse according to almost every quality of life indicator. In "The Spirit Level", they show that per capita GDP is much less significant for a country's life expectancy, crime levels, literacy and health than the size of the gap between the richest and poorest in the population. So the best indicator of a country's rank on these measures of general well-being is not the difference in wealth between them, but the difference in wealth within them.
But he has since reverted to Thatcherite type, treating the size of the gap between the rich and the poor as an irrelevance and offering only a more elegant version of Norman Tebbit's "get on your bike". "You’ve got to get out there and find people, win them over, get them to raise aspirations and get them to think that they can get all the way to the top," he said recently. The political field has been left open to Miliband.
In the days following the death of Tony Benn, many have remarked on how distant the debates that defined his era now appear. But the chasm that separates Miliband's stance on inequality from that of Cameron is the strongest evidence yet of why the next election will be defined by precisely the kind of big choices that have for so long been absent from British politics.