In Switzerland, further construction of minarets has been banned after a referendum on the issue (57% in favour). This seems to strike at the heart of many debates: the separation of church and state, between the religious and the secular, on referendum and the tyranny of the majority, and on human rights and minority rights. This law seems objectionable for two reasons; one relating to rights and the rule of law, and one relating to liberal democracy. The draw of the argument that a referendum trumps these because it's the "will of the people" may be attractive on a first glance, but if we look at what we mean by the rule of law and the purpose and extent of democracy, it soon looses its force.
It might seem strange to ask if a law passed by a referendum is "legal", but, just as states are limited in their sovereignty over their people, so the sovereignty of "the people" is limited over the individual. This is done by constitutions (though these can be changed - usually, but not always, by referendum), but it's also done through international conventions and treaties on human rights - in the extreme is the outlawing of genocide; a crime over which all states have universal jurisdiction, so that even if the sovereign power makes it legal within its borders (even through referendum and the will of the people), other states can prosecute the perpetrators on their territory.
So is it legal? The EU Law Blog has a good article on this, and argues that it can't be held to be legal, since it violates the right to religion. there have been counter-arguments that the right to practice religion is qualified in its public form, but this misses the point that qualifications on rights must be justified. The referendum result cannot be this justification, just as "the state passed a law" cannot be in itself a justification - there must be some public necessity based on public health, order, etc., in order to limit the rights of individuals.
I very much doubt that any firm reason of public necessity can be given: only minarets are banned, not church spires or church bells, and the minarets that are already built will remain. The law is manifestly discriminatory, as it enforces a ban on one community without applying the same restrictions to others in similar positions, and without a set of valid reasons. On this basis it probably violates the European Convention on Human Rights, which Switzerland will ironically be chairing (though hopefully they won't be chairing it ironically).
It's because it violates this tradition of rights and raises the spectre of discrimination between religions that Julien Frisch has denounced the referendum as a Europe he wouldn't vote for. On its own, I think the above argument is enough - that not only is it a violation of rights, but an unjustified one.
Some may still argue that despite the rights-based argument, and arguments against the tyranny of the majority, the result is democratically legitimate and that should trump any other concern.
But to do so would be pushing towards breaking the distinction between the public and private spheres in liberal democracy. should everything be within the public sphere - or subordinate to it? Should everything be subject to the sovereignty of the state/people? Generally we consider the private to be superior - and that the public needs a good reason to interfere in the private sphere. Let's apply that to this case: this concerns private individuals, building on privately owned land with their own funds. The state is not involved. There are no planning permission-based objections. So we would say that the public sphere (in this case the state acting as an agent of the will of the people) needs a proper reason of public concern to interfere.
Extend it further: what if a private individual built placed a statue to the Virgin Mary on their land. Such statues aren't essential to Catholic worship/expression of religion, but they are a private expression of religion. Would a referendum banning the erection of statues of the Virgin Mary be legitimate? No; we'd say that it's an arbitrary rule that doesn't follow the rule of law. If it was a law banning the erection of all statues, the law would be more rational and less discriminatory, though it would still be unjustified - on what basis can the state intervene? If the complaint was that there was unreasonable light pollution from the light illuminating the statues, then there may be the beginnings of a reason if it: (1) could be proved that the light pollution was serious enough to be of real public concern, (2) there was no other way of preventing the light pollution. It would fail because: (1) it leaves the already erected statues alone, (2) the lights are at issue, not the statues themselves and the lights should be subject to a ban or a form of regulation to ensure they remain within certain limits. On the basis of religion, culture or politics objections, how is the statue adversely affecting the rights of others to religious, cultural or political expression? It doesn't.
This issue is not only about democracy and human rights, but on the extent of the state, the rights of the individual and the rule of law. There cannot be a coherent argument for the decision on the basis of democracy unless it's from the position that the will of the sovereign trumps everything, every time.
And I can't accept that level of state power.