Whether religious freedom is a concept worth supporting really depends on what it means. No one wants to be heard saying that they are opposed to it, but not every conception of it is as liberal as the one that I support. I'm currently reading Michael J. Perry's Under God? Religious Faith and Liberal Democracy. At this stage, I haven't absorbed the whole thesis, and there are some points to come that I'll probably find attractive. But he does seem to think that, for example, there is nothing wrong with politicians voting to ban conduct merely because it is against their moral views, and even though they would not have those moral views except for their reliance on a holy book. Thus, if a society dominated by people whose holy books say that eating pork is an abomination decides to ban eating pork that is fine ... even though the ban is not for public health reasons, or because there is a temporary shortage of pork so all pigs must be used for breeding for the time being, or whatever other secular reason we can imagine, but merely because the relevant holy books condemn the eating of pork.
Needless to say, Perry's ideas of what a government can do in a society that embraces religious freedom are radically different from mine. For me, the above is a paradigm example of a religious doctrine being imposed on population - believers and non-believers alike - by means of the coercive power of the state. And whatever else that is, it is not freedom of religion.
Of course, Perry is correct that in the real world of Western democracies such as the US it will be difficult to find such clear-cut examples. For example, people who think homosexual acts should be criminalised can always dream up some kind of secular-sounding reason. But that's not a reason for us to stop complaining about essentially religious doctrines being imposed by the state and backed up with guns and police: "We will force you not to have sex with the person of the same sex whom you love, or between whom there is simply a mutual attraction, on pain of locking you away in a small space behind iron bars, and even though you are not hurting anyone and don't accept the holy book on which we base our decision to do this."
No, that's not acceptable. That's tyranny.
Even if the state can get away with banning X for what are preponderantly religious reasons - e.g. by convincing a constitutional court that it also had some secular reason - so what? This does not give us a reason to say that banning X for preponderantly religious reasons is consistent with plausible ideas of what freedom of religion is all about, or that banning X for preponderantly religious reasons is a proper thing for the state to do.
I'll read further as the week goes on. Although it's a short book, it's very densely argued (to its credit), and the issues are, at least from my point of view, extremely important. So I'll take my time, make close notes, and so on. I can see, looking ahead, that Perry is going to qualify his argument considerably, but I can't see him doing so to an extent that will mollify me.