If you haven't yet heard of Thomas Piketty, the chances are you will before long.
A French economist turning in a book of 640 closely-argued pages might not sound like author of the month, but Capital in the Twenty-First Century is one of those works that catches a moment.
It says, with statistical chapter and verse, that what you suspected about the modern world is true. It shows that wealth inequalities are almost as bad as they were a century ago. It demonstrates that inherited capital, the stuff of dynasties, is back as a driving force. It explains, clearly, what happens when you give up on redistribution.
Most of us have heard a bit of this. Stagnating wages, corporate greed, the rise of "the 1%", the end of the shared prosperity of the post-war years: we can read the headlines, we can say how it feels. It counts as lived experience for millions and it is no longer explained away by recessions, no matter how severe. Wealth has shifted decisively.
So what should a politician say to that? If you happen to be Ed Miliband, you might call it a "cost of living crisis". That doesn't quite convey the sense of a profound historical event, but it will do for a sound-bite. A crisis is the sort of thing a decent leader is supposed to address and solve with a few astute policies. Systemic failures can be left to French professors who don't have to fight general election campaigns.
Mr Miliband is in a tricky position, however. He knows that inequality's consequences matter greatly to those hard-working families who populate a politician's mental landscape. He also knows that a challenge to a rigged economic game would contest the received wisdom of 40 years and, come to that, received wisdom within sections of his party. If you talk about inequality in this United Kingdom you are, by definition, left wing and unfit for government.
Ed isn't red, not by conviction, but he also fails to strike enough people as being fit for Downing Street. The latter fact is his burden. Justly or not, he fails to match the weird criteria of modern electoral politics. Labour thus has a programme it cannot quite declare and a candidate it cannot easily promote. It also expects the next UK general election to be a nasty, negative affair. What's to be done?
David Axelrod is not the first American to come to the aid of the party. Labour has established something of a tradition, in fact, of borrowing tactics, policies and personnel from its second cousins among the Democrats. Tony Blair and Gordon Brown copied much from Bill Clinton. Election strategists have been enlisted regularly down the years while rising Labour stars have pursued apprenticeships on American campaigns. Mr Axelrod is something more, however, than a high-class exchange student.
His claim to fame is that he, as much as anyone, won the presidency for Barack Obama. More importantly, Mr Axelrod was also crucial, so it is said, to the re-election campaign. In the consultant's telling that battle was marked by a shared understanding of what mattered to voters in 2012: by no coincidence, that too was a cost of living crisis.
Or as Mr Axelrod told the Guardian the other day, Mr Miliband understands, as Mr Obama understood, that "We can't just have prosperity hoarded by a few where people at the top are getting wealthier and wealthier but people in the middle are getting squeezed". The consultant added: "Barack Obama articulated a vision which had, at its core, the experience of everyday people. And everyday people responded, they organised and they overcame the odds. I see the same thing happening in Britain."
Mr Axelrod, whose company will receive a "six-figure sum for his services", neglected to discuss the tiny fact that Mr Miliband is not, by any stretch, Barack Obama. It can't have escaped the strategist's notice. The Labour leader might be at least as astute as the Democrat in his understanding of the issue of inequality and its consequences. The difference is that when Mr Obama speaks, people listen.
British parties hire their foreign campaign specialists for a simple reason: the visitors are supposed to possess the secret of winning. The assumption, questionable to say the least, is that what works in one country will work in another. But if it works, or seems to work, no politician ever complains.
So Labour brings in Mr Axelrod, an operator who has claimed the most prized laurels of them all. The Tories meanwhile have Lynton Crosby, the Australian who helped John Howard to four election victories in his country and bestowed a self-described mastery of "dark arts" on Boris Johnson's 2008 campaign in London. The parties, like these consultants, are always open to offers. What they believe matters less, much less, than what works.
A striking illustration of the fact was provided by another recent American recruit to the Conservatives. Jim Messina is a former deputy White House Chief of Staff, an expert in voter research and social media. Mr Messina is a big deal. He also happens to be another veteran of Mr Obama's campaigns, hired not for his beliefs but for his knowledge of the strategies adopted by the re-election candidate when a crisis was laid at his door. You might have guessed: the 2012 American cost of living crisis.
No one suggests that Mr Miliband and David Cameron intend to stage a blatant re-enactment of an American political battle while reducing serious economic arguments to a few slogans. Should the need arise, however, each man will have an imported adviser at his ear and the requisite playbook at his elbow. It might not be the response desired by Professor Piketty or voters fearful for the future, but this, today, is how political products are sold.
The French academic takes it as given - and demonstrable - that economic growth in the west is in long-term decline. As a direct consequence, capital and wealth are being concentrated in a few grasping hands. Yet when the Westminster parties go to the country in 2015 a vast global shift will be packaged up and quibbled over as "a cost of living crisis", with foreign political hacks supplying the script. Such is our democracy.
No one should pick on Messrs Axelrod, Crosby and Messina. They have marketable experience and skills. They know all the tricks. They have helped candidates to win against the odds. Their faith in their knowledge of all the buttons a campaign must press runs deep. They have to make a living, like all of us.
Then again, since when was the American system held up for admiration? More to the point, how has Mr Obama's grasp of "the inequality issue" been manifested since his re-election? The top 1% of Americans command 50% of income; Britain is following the same path. In the face of such realities, great campaigners and their clever advisers stay silent.
Mr Axelrod might defy the odds and help Mr Miliband into Downing Street. What then? Then all the consultants and advisers will set to work plotting the next campaign. The real crisis, vast and deep, will keep.