Whatever the eventual outcome of this election, the voters have spoken already. The political landscape changed suddenly after the first televised leaders' debate, when support for the Liberal Democrats soared in a way that was without precedent in the middle of a campaign. "Cleggmania" was the equivalent of a loud cathartic scream from a bemused, frightened and angry electorate.
The noisy eruption was more shapeless than it might have seemed at first. I doubt if many of those turning towards Nick Clegg knew too much about what was in the Liberal Democrats' manifesto. Probably their disillusionment with the traditionally bigger two parties had little to do with what either Labour or the Conservatives were proposing at the election. But voters saw in Clegg a figure who could perhaps guide them away from stifling political orthodoxy as represented by the old duopoly. This recognition, however vaguely formed, had in its origins a refreshing clarity. A majority of voters yearn for a new way of conducting politics.
We need to be careful about how to interpret the appetite for change. There is always a hunger for something "new". Disillusionment is the easiest and laziest emotion in politics and probably in life more generally. Novelty has always had superficial appeal. In the early 1980s there was a similar excitement around the advent of the SDP, but the ambition to break the mould came to nothing. Instead, Margaret Thatcher won landslides on the back of a split left.
In 1997 Tony Blair recognised the value of novelty by placing the adjective "new" in front of his party's name. New Labour won historic landslides promising a dramatic break with the past. The art of winning elections is to tap into voters' capacity to be easily alienated. It always has been.
In this sense, Cleggmania was not really a new phenomenon. But the context made it fundamentally different. The backdrop to the election campaign is both an economic crisis of apocalyptic proportions and a parliamentary scandal. The near collapse of the banks and the reckless greed that brought it about should be enough to shake up politics on its own. When the MPs' expenses scandal is added to the brew we have a combustible combination.
The sudden increase in support for a third party once the election was underway has been one consequence of changes that are taking place in front of our eyes. Who would have though that the government would own several banks? Who would have thought we would be accumulating an intimidating debt to stay afloat? Political change is partly a response to wild events elsewhere.
There is another factor in the hunger for political reform. In trying too hard to please as many voters as possible, Labour and the Conservative parties have blurred their identities to a point where few have any sense of what they represent.
The reason why this has happened is not arrogant indifference to the voters. Often during this election campaign I have heard "vox pops" of fuming voters declaring mistakenly: "The politicians don't listen to us. They take us for granted."
The precise opposite is closer to the truth. Desperately insecure, conscious of their vote-losing pasts, senior figures from the Labour and Conservative parties have listened too hard. New Labour in particular was not arrogant enough in its insecure desire to please.
Instead, in both cases, principled thoughts and objectives – they do have them – are crowded out by focus groups, opinion polls and the noise of the loudest, most bullying newspapers.
New Labour tried to do whatever it took to reach as wide an audience as possible. Tax cuts for the very rich, light regulatory regimes for bankers, an authoritarian approach to crime and public order and even the war in Iraq were instigated partly on the assumption that they would in the end widen the party's support and, in their counter-intuitive implementation, deprive the Conservatives of purpose.
In the end, the very measures Tony Blair and Gordon Brown adopted to reassure doubters brought about their downfall. Labour ceased to be a recognisably coherent party on the centre left long ago. Its lifeless campaign in this election is partly the consequence of there being little life.
David Cameron has been less drastic and arguably not drastic enough in his approach to the Conservative party. He has left many of the most contentious policies from previous elections in place – Euro-scepticism, tax cuts, a small state – but projected them in a new light and embraced the values of social liberalism adopted by most of the country decades ago. This is not enough for progressive voters seeking an alternative to Labour.
The precarious nature of Cameron's support was evident when Clegg seized the mantle of change in a single debate. If Cameron had truly modernised his party Clegg would not have had any space by the time of the debates. Instead, Clegg espouses a politics that might have been Cameron's if he had seriously changed his party. Clegg is pragmatically pro-European, a constitutional reformer, an advocate of sweeping redistribution through the tax system.
But he is not a social democrat, having explicitly stated that in his view the social democratic experiment has failed in Britain. Some would argue, including quite a large section in his party, that social democracy was only erratically applied. None the less, Clegg articulates a partially fresh agenda, and for the first time since the early 1980s voters have rushed to hail the third party as an alternative to the other two.
There are grounds for hoping that the sclerotic status quo cannot survive this time around, as it did in the 1980s. The decline in support for the two parties has accelerated in recent years, making the current electoral system even more unsustainable, a great clumsy distorting instrument. Labour won a substantial majority in 2005 with a puny level of support amongst the electorate as a whole. The result gave an impression of Labour dominance that was wholly artificial, as damaging for the governing party as it was for the wider political culture. More perceptive cabinet ministers argued privately then that there was a strong and potent anti-Labour mood forming, one that was obscured by the result.
Since then, support for the Liberal Democrats and what polling organisations call "Others" – the smaller parties – has grown considerably. Once again they will not be represented in the new House of Commons.
Instead, it is quite possible the David Cameron will secure an overall majority and the chance for fundamental change will pass. He is opposed to electoral reform, the act that would unlock the current system.
Do not underestimate how easy it will be for the energy unleashed in this campaign to be put back into a box. If the Conservatives win a majority, much of the media will quickly focus on more immediate dramas: the new cabinet, George Osborne's "emergency" budget, a Labour leadership contest, the dynamics of a Prime Minister's Question Time in which a new Labour leader would face a new Prime Minister and Clegg would be back to asking his two questions a week, largely ignored in the excitement.
There might well be enough novelty to blow away the current focus on fundamental reform.
Only a Lab/Lib partnership would guarantee change, as both are committed to electoral reform. If Cameron is Prime Minister he might have no choice but to address the frustrations that have taken a slightly more tangible form in the election. He is an astute reader of the public mood and might feel compelled to respond, but he has quite openly stated his opposition.
I agreed with him for a long time, becoming a late convert to electoral reform after observing how Labour ruled with its landslide majorities. Largely, Blair/Brown ignored the Commons, yet they were obsessed with some non-elected newspapers. Rupert Murdoch was far more important to them than any member of the cabinet.
Some of their biggest mistakes might have been avoided if they had been compelled to listen to the Liberal Democrats and Green MPs in order to win votes in the Commons. In spite of himself, Blair might have travelled a more progressive path, rather than one navigated to meet the enthusiastic approval of the Sun newspaper. If Brown, as Chancellor, had been forced to listen to Vince Cable at times rather than seek to please right wing newspapers, perhaps he would not have needed to appear so close to the bankers in order to seem "respectable".
We should not romanticise. Coalition politics would be messy, and the Liberal Democrats would need to display a clearer sense of unified, pragmatic purpose. Their divisions have been largely hidden – but not for much longer. Clegg's party will deserve wider attention from now on and will get it. Scrutiny is the reward and price of success.
The old economic assumptions have collapsed. The last parliament became the rotten one. The previous one voted for a war opposed by most voters. The voters' scream in this strange campaign deserves a response in the aftermath. They will not keep quiet until they get one.
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