At this turning point in our political history, when the global economic crisis has made a mockery of the free-market ideology that has dominated western politics since the age of Reagan and Thatcher, and Britain's Labour government seems to be staggering towards the exit, we should feel we are in exciting times. This, surely, is a moment when the electoral landscape is about to be redrawn and the boundaries and ambitions of political debate established for decades to come, just as they were at the advent of Thatcherism in 1979 or after the Attlee landslide in 1945.
But one thing is missing, perhaps the most important thing of all: the big idea. If we are at a watershed in modern history, where is the torrent of initiatives that will remake our world? Where are the thinkers who will banish the post-Thatcherite orthodoxy and come to define the 2010s as John Maynard Keynes and Milton Friedman dominated previous political eras? And why do our political leaders - intelligent, thoughtful men and women, educated at Britain's finest institutions - seem so painfully and embarrassingly short of new ideas?
A cynic's answer would be that it was ever thus - that when Gordon Brown switches on his robotic auto-response, listing statistics that supposedly show Labour's achievements, he is merely following in Clement Attlee's footsteps; that when David Cameron delivers the smooth pieties about change and renewal, he is doing just what Margaret Thatcher did in the run-up to 1979. But that is simply not true.
When Attlee won power in 1945, for example, his Labour government was suffused with crusading zeal and an intellectual mandate to build
a "new Jerusalem" on the foundations of Keynesian economic management, full employment and a generous welfare state. And even during the last great watershed in the late 1970s, politics was alive with ideas and ideological division in a way that now seems almost prehistoric. As the late Ben Pimlott once wrote, the Tory revival of the 1970s was driven by ideas - the free economy and the strong state - that "came from outside, creating a groundswell of sympathetic opinion before their adoption by the Conservative Party leadership". Thanks to organisations such as the Institute of Economic Affairs, the Centre for Policy Studies and the Adam Smith Institute, Thatcher's handbag was stuffed with policies on everything from selling off the family silver to scrapping the NHS and replacing comprehensive education with a voucher system. Many never saw the light of day, but they added up to a formidable laundry list driven by the belief that, as her ally Ronald Reagan put it in his first speech as president of the United States, "Government is not the solution to our problems; government is the problem."
Historians still argue about the extent to which Thatcher and Reagan understood the ideas associated with their political careers. Did Thatcher really slam down a copy of Hayek's Road to Serfdom with the words "This is what we believe!", or is it just a compelling folk legend, told by senior Tories to impress their young? But there is no doubt that they fed off ideas to an extent almost unimaginable today, just as the guiding lights of the Attlee government - Ernest Bevin, Aneurin Bevan, Stafford Cripps, Hugh Dalton and Herbert Morrison, as well as the prime minister - drew on the extraordinary ferment of ideas in the late 1930s and 1940s, epitomised by William Beveridge's landmark report on social insurance.
That Labour's ideological cupboard seems so glaringly empty is perhaps not surprising. Any party that has been in power for 12 years is bound to find itself intellectually exhausted; if nothing else, its senior figures become so used to defending the records of their departments that their narrow, negative rhetoric becomes almost second nature. Nobody doubts that Ed and David Miliband, for instance, are bright and thoughtful. The problem is that, buried under mountains of paperwork, they simply do not have time to think deeply about Britain's current situation. And beyond that is a deeper but very obvious problem: New Labour's ideological dependence on Thatcher's legacy of free markets, deregulation and a highly centralised welfare state.
If there was a moment when Labour could have broken away, that came in the early to middle 1990s, when the Major government was in its death throes and thinkers such as Will Hutton were urging Tony Blair to adopt a retooled version of European social democracy. But with the economy entering a long period of unprecedented growth, Blair and Brown preferred to stick to the template of Thatcherism, banishing from their speeches the very word socialism, even as an empty signifier of egalitarian intent. The problem was that when boom turned to bust - as it always would - they had nothing to fall back on, which is why Brown's cabinet, stuffed with greasers and fixers, is such an intellectually arid wasteland.
More might be expected of David Cameron's mob, who in the past few years have shown signs of at least thinking seriously about their image and place in a fluid, diverse society. And yet it is almost impossible to discern any genuine ideological vision behind the tree-hugging photo ops: ask Cameron what he wants for Britain, and the answer is likely to involve strong families, safe streets and stable public finances - in other words, a list of clichés with which nobody could possibly disagree. There is no sense, for instance, of him being informed by perhaps the only genuinely innovative political idea of the past few years, Phillip Blond's "Red Toryism", which calls for a decentralised conservatism breaking with laissez-faire capitalism and favouring traditional values, local communities and small businesses. Instead, Cameron's basic argument seems to be that he will do exactly what New Labour has been doing, only better. That he once described himself as "the heir to Blair" says it all; by contrast, Thatcher describing herself as the heir to Harold Wilson, or Attlee describing himself as the heir to Stanley Baldwin, or Lord Salisbury laying claim to Gladstone's mantle, simply beggars belief.
A common explanation for the death of political ideas is that we live in a post-ideological age, in which grand narratives have been discredited and broken up, much like the heavy industry and public utilities of the 20th century. But surely this is highly exaggerated. It is true that Marxism as a practical economic blueprint lost what remained of its appeal with the fall of the Soviet Union; in a globalised world, a return to state socialism seems even less likely than Brown going down in history as one of the great communicators. Yet even though academics and intellectuals may scoff at the notion of grand ideological narratives, there is little evidence that the general public has lost its appetite for big ideas. One reason for the appeal of the British National Party, after all, is that it offers a simple and compelling story that makes sense to working-class former Labour voters. Moreover, there is no sign of religion dying out as a global force. And in their different ways, the anti-globalisation and green movements reflect the same hunger for ideological commitment and crusading mission - values that have almost disappeared from the arena of electoral politics.
Perhaps a more plausible explanation is simply demographic. Most of Britain's major politicians came of age - either literally or metaphorically - in the late 1980s, when free-market ideas were carrying all before them and resistance to Thatcherism seemed antediluvian, backward, even futile. It is surely no accident that the likes of Cameron and James Purnell took their first political steps during the Major years, when Thatcherism had lost its shock value and become the new consensus, and when senior figures in both parties routinely dismissed dissenting opinion as "unrealistic" adolescent idealism. It is a rare politician indeed who changes his fundamental ideas after he has reached the top, or even after he has reached his thirties. Even those who famously changed parties, such as Joseph Chamberlain or Winston Churchill, never changed their basic convictions. And it is even more difficult to change your mind, to reach for new ideas, to test new conceptions of state and society, when you are a public figure in the glare of the spotlight, the press ready to pounce at the first sign of inconsistency. Safer, surely, to steer clear of ideas altogether, as Cameron's opinion-poll lead seems to prove.
But there is another reason that says something rather depressing about the nature of modern politics. By and large, political leaders have always been heavily dependent on others for their ideas. Even those politicians we most associate with ideological watersheds - Roosevelt and Reagan, Attlee and Thatcher - depended on "brains trusts" of academics and advisers, such as the rolling seminars that Reagan's Californian aides arranged with foreign policy and economics experts when he was running for the presidency in 1980. But Reagan was then in his late sixties and had been in politics, one way or another, for more than 30 years. He had had years to listen to advice, to read conservative magazines and policy papers, to sift through ideas - just as, say, Attlee had been politically active for 25 years before he became prime minister.
By contrast, Cameron entered parliament in 2001, little over ten years after he graduated from Oxford. In the intervening period he worked for the Conservative Research Department, usually for more than 12 hours a day, then as an adviser at the Treasury and Home Office, and then for a communications firm. It is a familiar career trajectory, not dissimilar from those of young Labour high-flyers such as Purnell, Yvette Cooper and Kitty Ussher, all of whom in effect went straight from Balliol College, Oxford, into the Commons, with a few glorified gap years as special advisers or economics researchers in between. As career paths go, it hardly brings them close to the people they represent. Instead, modern politicians often step from one rarefied bubble into the next. What we have ended up with, therefore, is a kind of two-bit version of the French École Nationaled'Administration system, with a political class trained at Oxford and Cambridge, given a couple of years as special advisers, and then catapulted into safe seats and junior ministerial jobs - a world in which ideas play no significant role, other than as revision material for Oxford PPE exams.
It is all too easy to idealise the past as a golden age and to demonise the present as debased and dumbed-down. But in his splendid new book Pistols at Dawn, a study of political rivalry since the age of Fox and Pitt, the distinguished biographer John Campbell argues that there was a golden age of political seriousness, roughly between the 1870s and the 1960s, when politicians "took the business of government very seriously" and tried to "communicate seriously with what they still imagined to be an informed and interested public opinion". There may have been an element of self-deception in all this; politicians probably "imagined the public to be more interested than it really was". But in an age before focus groups, there seemed to be no benefit in appearing stupid: while Tony Crosland loved Match of the Day, he made no great public display of his interest in football, and was better known as the author of The Future of Socialism. The contrast with Brown, a highly intelligent man with a doctorate on James Maxton, is almost excruciating to contemplate. Certainly it is difficult to imagine Crosland or his friend Roy Jenkins sitting on the GMTV sofa and earnestly relating late-night phone calls to Piers Morgan and Simon Cowell.
The irony, therefore, is that as politics has become more ostentatiously open, with cameras recording Commons debates and committee sessions, so it has become increasingly populist, with politicians keen not to advertise their intellects in case they appear to be lording it over the voters. Overtly intellectual politicians, such as Lord Adonis or David Willetts, are generally kept away from the cameras, and are an increasingly rare breed anyway. What we are left with is a political scene that seems a long way from the bitter ideological debates of the 1930s, or even the great Gladstone-Disraeli clashes of the Victorian age, but is unavoidably reminiscent of the 18th century - a world of "patronage, self-promotion and mutual back-scratching", as Campbell puts it, "where there is nothing at stake but the achievement and retention of office and the opportunities for personal enrichment that it brings". In many ways this offends our instinctive sense of what politics should be about. Whatever happened to politics as the battleground of ideas, the clash of ideological forces, the collision and resolution of deeply opposed class or sectional interests?
The answer is surely that, at some basic level, politics has never been about those things. Before the advent of democracy, after all, politics was simply a struggle for power, in which different noblemen or courtiers competed for the king's ear and patronage, taking up and discarding policies as they proved useful or otherwise. As late as the 18th century, the crucial division was between court and country - in crude terms, the ins and the outs. Even in the age of the French Revolution, Edmund Burke and Mary Wollstonecraft, political rivalry was rooted more firmly in factionalism than in ideology.
The emblematic rivals of the era, Charles James Fox and William Pitt, are seen today as symbols of broad political traditions: on the one hand, Fox the Romantic, idealistic representative of parliamentary reform, peaceful internationalism and popular sentiment; on the other, Pitt the patriotic war leader, the cool defender of property rights, sound money and the free market. And yet in many ways these were differences forced on them by the pressure of their incompatible ambitions. At first, Fox welcomed Pitt as a protégé; later, after joining forces with his former enemy Lord North, Fox encouraged Pitt to join their unlikely coalition. Theirs was a world not of fixed ideological opposites, but of shifting factional alliances, in which an ambitious politician might move smoothly from one camp to another - just as Brown's new best friend, Shaun Woodward, formerly John Major's campaign chief, changed his affiliation from Tory to Labour.
We may well laugh at the self-interested antics of politicians such as John Bercow, the former Monday Club member-turned-oleaginous admirer of Brown, who shrugs off ideological affiliations as easily as a snake sheds its skin. Yet to a politician such as Lord Palmerston, who entered politics as a Tory in 1807 and died in the saddle as a Liberal in 1865, having spent almost all the intervening years in one government or another, such behaviour would have seemed perfectly normal - just as it did to Churchill. Once a Tory, then a distinctly pinkish Liberal, the man voted our greatest Briton ended his days as a highly reactionary Tory once again. "Anyone can rat," he remarked, "but it takes a certain ingenuity to re-rat." A lesson there, perhaps, for Woodward?
All this is not to say that ideas no longer matter, or to deny that the coming years will bring major ideological clashes over, for example, the future of globalisation, the expansion of the European Union, or the best way to reconcile economic growth with environmental responsibility. But we are living in a political age that would surely be much more hospitable to Fox and Pitt than to Gladstone and Salisbury or even to Attlee and Thatcher, with parliamentary politics as a self-interested game played by a small, narrow and highly educated political class, physically, morally and intellectually detached from the constituents they are supposed to serve - which explains why, to use a refrain often heard over the past few weeks, "They just don't get it." Politicians not getting it, just like politicians ratting and re-ratting, seems likely to be an increasingly conspicuous feature of our national life in the next few years. It is not just that senior politicians tend to be absurdly young, or that their horizons are limited to Oxford, Cambridge and London; even their friends and family tend to be drawn from the same political class. It is no wonder that so many people refuse to vote, or spoil their ballot papers, or turn to fringe parties, when the Tories pick candidates such as Benedict Gummer (age 31, educated at Cambridge, son of John Gummer) to fight Ipswich, or Labour tries to force Georgia Gould (age 23, educated at Oxford, daughter of Philip Gould) on to the voters of Erith and Thamesmead.
Many readers may argue that it is a mistake to look to Westminster for ideological argument and intellectual conviction; that, in a fluid, post-modern, decentred age, in which the personal is political and all politics is local, what goes on in the Houses of Parliament no longer matters. I do not share that opinion. As the past two years have shown, there are some issues, from the banking crisis to climate change, from the conflict in Afghanistan to the future of our public services, that can be decided only at the national level, by politicians arguing on the Commons floor and taking decisions in cabinet. It has become a cliché to say that as a society we face huge challenges and difficult choices, but that is partly because it is true. And it is a shame that at such a critical moment we find ourselves with a political class who have so little to say about any of them.