immigration, Scottish independence, Ed Miliband's knowledge of local politics and Nigel Farage's attitude to race. What it hasn't really been about is Europe, at least not in a practical sense. There has been remarkably little actual discussion of where the European Union is going and what Britain's place in it should be. Is this a superstate juggernaut careering to economic ruin or the most successful economic union in history? And is Britain in or out?
The big questions have been closed off by David Cameron and Ed Miliband's referendum "locks" that defer decisions until after the next General Election. They frame the debate with a presumption that the EU is something alien that needs to be kept at arm's length. The Prime Minster says that, if he doesn't have a repatriation of powers from the EU, he will campaign for "Brexit" in an in/out referendum in 2017. Mr Miliband says that, if any more powers are sought by Brussels, he too will trigger an in/out referendum. Both the main UK parties tacitly endorse the populist view that Brussels is "too powerful" and needs to be "cut down to size" while Britain needs to act to preserve its "sovereignty".
What neither seems very interested in talking about is which powers should be repatriated or rejected. Conservatives generally cite the "bent banana" regulations that define Europe in the tabloid mind. "The institutions of the European Union regulate everything from the hours we can work to the price of our food to the width of our condoms," says Boris Johnson, perhaps revealing his own priapic preoccupations.
But where these have not been fiction, they have mostly been regulations establishing common standards across the 500 million-strong single European market. Tories also regularly cite the European Convention on Human Rights as an importation of politically correct EU law, even though it has nothing directly to do with the EU. It was a codification of anti-totalitarian rights devised after the Second World War by European leaders including Winston Churchill.
Social and employment law is the other main area in which Brussels is said to have taken unwarranted powers to intervene in UK affairs. As far as I can make out, this seems to mean mainly the Working Time Directive. This is certainly high on Foreign Secretary William Hague's list of Euro impositions, even though British workers can opt out from its key provision, limiting the working week to 48 hours. The Social Chapter of the Maastricht Treaty is similarly regarded as a real and present danger to British economic freedom.
But this is a list of unobjectionable measures on sex discrimination in the workplace, health and safety standards, workforce consultation and annual holidays. It has nothing to do with pay levels or trades union rights or economic management.
The founding principles of the EU are free market ones. Of course, the main reason many people dislike Europe, including a lot of Scots if the poll findings revealed in yesterday's Herald are any guide, is not legislation but immigration. The perception is that Brussels has forced Britain to accept millions of migrants from dodgy countries such as Bulgaria and Romania who are milking the UK benefits system and importing crime. Even Mr Miliband says he will bear down on migrants and Labour politicians can hardly open their mouths on Question Time without saying they were "mistaken" about immigration when they were in office.
Yet it was Britain in the 1990s that argued for the EU to absorb the Eastern European countries after the collapse of the Soviet Empire. And it was Margaret Thatcher who argued for the free movement of goods, capital and labour as cornerstones of the single market. This inevitably means migration between member states as people go to where the jobs are. It is inconceivable that Europe will reverse this freedom of movement. Boris Johnson is right when he says it is "deceit" to claim EU immigration can be halted without leaving the EU.
If Britain is so fundamentally opposed to the very foundations of economic union, what future is there in remaining within it? There is a lot wrong with Europe, not least the lack of democratic accountability of its central institutions. But Britain seems likely to veto any of the measures needed to address its defects. The parliament needs to be strengthened and given greater control over the Brussels bureaucracy. But this might diminish the powers of nation states to reject laws enacted there and would be opposed by the UK. Nor are we likely to endorse reforms to prevent sovereign debt crises.
The euro is in many ways a great economic achievement. It boosts economic growth and free trade by abolishing transaction costs and economic borders. It also, as the founding fathers of Europe understood, makes conflict all but impossible between member states. Countries in monetary union cannot engage in competitive devaluations or raise tariff barriers, the precursors to war in the 20th century. We can scoff at the idea of war in Europe but events in Ukraine show that conflict can still break out without warning.
Many expected that civil conflict would propel benighted Greece out of the eurozone in 2011 when "Grexit" headlines were all over the UK press. Many distinguished economists including Paul Krugman and Nouriel Roubini said the euro was finished. But Greece voted to keep the euro and, since then, things have stabilised. Borrowing costs in countries such as Spain and Italy have returned to normal. Ireland, which was also forecast to leave the eurozone, seems well on the way to an export-led recovery. But unemployment remains a massive problem with rates of 20% or more in many southern European countries. This is the greatest problem with the EU: its failure to place growth and jobs at the top of its agenda. The EU needs to address this by creating the institutions of a fiscal union, a central treasury with financial powers to support economies in difficulty.
When Mario Draghi, president of the European Central Bank, announced in 2012 that Europe would do whatever it took to stabilise member states' currencies, he willed the end but not the means. As the governor of the Bank of England, Mark Carney, has pointed out, Europe still has to create a new centralised system of fiscal controls and balances, and this is almost certain to require greater powers for Brussels and "ceding of sovereignty". Indeed, some of these powers were in the banking union that Britain tried to veto in 2011. Europe went ahead regardless.
So are we in or are we out? I simply don't know and this campaign has left me none the wiser. But it is hard to see how Britain is going to remain in this increasingly integrated economic space. The half-in/half-out approach cannot last because Europe must inevitably move to "ever closer union" as Maastricht put it. David Cameron said yesterday that he would reverse that principle. If he is serious these could be the last European elections in which Britain participates.