The Court justified itself on this basis:
"As opposed to other international treaties, the Treaty instituting the E.E.C. has created its own order which was integrated with the national order of the member-States the moment the Treaty came into force; as such, it is binding upon them. In fact, by creating a Community of unlimited duration, having its own institutions, its own personality and its own capacity in law, apart from having international standing and more particularly, real powers resulting from a limitation of competence or a transfer of powers from the States to the Community, the member-States, albeit within limited spheres, have restricted their sovereign rights and created a body of law applicable both to their nationals and to themselves. The reception, within the laws of each member-State, of provisions having a Community source, and more particularly of the terms and of the spirit of the Treaty, has as a corollary the impossibility, for the member-State, to give preference to a unilateral and subsequent measure against a legal order accepted by them on a basis of reciprocity.
It follows from all these observations that the law stemming from the treaty, an independent source of law, could not, because of its special and original nature, be overridden by domestic legal provisions, however framed, without being deprived of its character as community law and without the legal basis of the community itself being called into question."
None of this was written into the Treaty which the democratically elected governments of the member states had signed. The Italian government was certainly surprised to find it had abdicated its rights to make its own laws.
The Treaty of Rome was a treaty like any other, binding in international law and not in national law. The Treaty of Rome was not special and original: it was further reaching than other treaties, but not dramatically so. While, as the Court had done earlier in Van Gend en Loos, it was possible to argue that certain provisions had "direct effect" in national law, it was a significant stretch to argue that those provisions could contradict law created later by a national parliament.
All international organisations are of unlimited duration, have their own institutions and their own capacity in law, not just the EU. A country can transfer powers without transferring sovereignty. Indeed, the right to sign a Treaty is part of the definition of sovereignty. Agreeing to rules does not stop you breaking those rules. Breaking the rules doesn't mean you can get away with breaking them, of course. Breaking them certainly doesn't mean you can deny the legal basis of those rules. But that doesn't mean you don't have the power to break them.
To add insult to injury, in the case of Simmenthal II, national courts were told they had to set aside any national law that conflicted with European law. Judges that all their careers had understood their job was to apply British or Italian or Belgian law were now told they had to ignore it.
If the European Court of Justice had not appropriated to itself, without any foundation in the Treaty, the right to overrule the democratically determined laws of the member states, the history of the EU would be very different. The UK might not be suffering a referendum that has empowered racists and endangered our economy.
By claiming the power to overrule national law, the European Court of Justice had also opened the door for its terribly reasoning judgements in other areas of law to dominate member states; in particular in over-interpreting the rights of workers to move around the EU to stop any residual powers of member states to stop them. Who would have thought that 27 judges who had exercised free movement of labour (plus one Luxembourger) would approve of free movement of labour?
I appreciate it is moderately niche to dislike the EU because of the terrible reasoning of the Court. But I'm a law person, and it's sort of fundamental to my being. And the arrogance of the Court matches the arrogance of all of the institutions; the idea that the answer to any problem is more Europe. In the case of the Parliament, that being on a list a minority of people put a cross next to, often in protest votes, means that you are democratically accountable and the voice of the people.
The EU does not need to be undemocratic. As all laws have to pass the Council, which is made up of the democratically elected ministers of each Member State, including the UK, the idea that there is some "EU law" overruling UK law is nonsense; in the overwhelming majority of cases, EU law is UK law. But that is not at all how the institutions conceptualise EU law. To them it is a separate, "higher" body of law.
Democracy exists when people decide that a certain number of their neighbours are permitted to have power over them. The question "who is my neighbour" is central to this. Democracy does not exist without the nation-state. Unless we feel a sense of "us", there is no consent to power, just imposition. If EU law is to be supreme, either EU law is law created by "us" (of course, in collaboration with others who call themselves "us") or it is not democratic.
If I were starting the EU from scratch I would keep the product standards, workers' rights and all the rest; without them you don't have a genuine single market as countries compete on "non-market" factor. But I would heavily restrict the free movement of labour that has so damaged trust in the EU to countries that have reached a certain level of wealth (perhaps two thirds of the EU average). I would abolish the Commission and probably the Parliament, and keep only the Council. I would explicitly remove the powers the Court has claimed for itself.
I am not anti-European. I have studied and worked in other EU states and I have felt the benefits of interacting with people from all over Europe and the world. But students have been doing years abroad across the world for ages, and I could have got my job, and therefore the right to work, without the "free movement" as over-interpreted by the Court. I believe, too, in European solidarity. I follow the politics of other European countries avidly and I believe in supporting social democrats across Europe. I have friends from across Europe. There is such a thing as the "European social model", which I believe in fully, and "European culture", which, in its non-imperialistic guise, is pretty good.
I know that the EU will never carry out the reforms I would want if I were king of the Universe. So I am a Eurosceptic and I disagree with fundamental principles of the EU.
But I'm voting for the UK to stay in the EU.
The choice on offer is not between my ideal EU and the current EU. It is between the current EU and nothing.
Sure, a deal will be struck. But the EU will continue, and we will be part of nothing.
Nothing means trade barriers, either technical or financial, between the UK and its biggest trading partners. Nothing means restrictions on our rights to work and study and retire in other European countries. Nothing means a Tory bonfire of workers' rights, not (just) because the Tories are ideologically committed to it, but because it will be the only way we can compete outside the EU. Nothing means xenophobia and racism winning. Nothing means Nigel Farage and Boris Johnson. Nothing means a void where solidarity should be. Nothing means my friends being unwelcome in my country, and maybe having to leave.
The day after a vote to leave, the stock market will crash. The pound will crash, putting up prices and putting pressure on business profits. The week after, the first signs of recession will emerge. Projects will be cancelled, jobs will be lost. It's not Project Fear, it's common sense. When you put up barriers to trade, trade dies. Not all of it, not everywhere. But recessions are on an aggregate basis; and in any event, they create a vicious spiral until they are stopped. Job losses in one industry create losses in another and so on.
Debate can legitimately rage about the long term economic prospects of the UK after Brexit. It seems clear to me at least that an economy with fewer barriers will do better in the long term than one with more barriers. But you never know. However, it is quite frankly irrelevant. People will lose their jobs or lose their pay by the end of next week if we vote to leave. Prices will have gone up. More people will have found it more difficult to pay for everything next month as compared to last month.
There can be nothing, not even the European Court of Justice, that can justify such self-harm. While having reservations about the principle of free movement of people, I have absolutely no problems having a Lithuanian or Romanian neighbour, because I am not racist. I certainly won't risk my job so that he can lose his.
I wish the EU was capable of genuine democratic reform. It isn't. I have and I will argue about the legal illiteracy of the ECJ. But that isn't enough to engage in the economic illiteracy of leaving the EU, even for a stubborn law nerd.