I think maybe one of the key differences between you and I is that you are a deontologist and I am a consequentialist. On a theoretical level, I don't think individual rights really exist. They're just a convenient shorthand, some of the rules of rule utilitarianism.
I get the sense that you view them as genuinely fundamental. Like all deontology, it's a viewpoint that suffers massively from the act of enumeration. "This is not on the individual rights list, so there is no tension between liberalism and a full ban."
To me, the key to liberalism is the recognition that private enjoyment of a thing, whatever it may be, is a deeply relevant concern. The fact that we cannot observe or quantify anyone's private enjoyment doesn't mean we can ignore it. Rather, it means we have to be extra careful.
A few points: (1) You're absolutely right that I am not a fan of a utilitarian approach to constitutional law! What I prefer is, you know, a... legal approach. The law is what it is, and the goal is to apply it and understand it as best we can.
(2) A rights-based approach to the powers of government absolutely need not be subject to the enumeration critique you make. We have an entire Ninth Amendment for that! There are techniques of finding individual rights in constitutional law other than "it's explicitly listed in the text"
(2) (con't) ...and I in particular am known, to the extent I'm known for anything, for my love of those techniques and my disdain for viewing constitutional rights as things that come from particular provisions! (3) The idea that, if "no one" wants to do X, it's not worthy of constitutional...
...protection runs aground, hard, on the part where the point of constitutional rights, and of constitutionalism generally, is to protect minorities, potentially very small ones, from being made to conform with the views of the majority! Hence the example of very small religious sects.
(4) Of course individual preferences matter! They matter, in the first instance, for the practical politics of democratic legislation. Outside the zone of individual rights, the protection people have for their general interests is the protection of the democratic process.
(5) ALSO, while you are of course correct that a right to pursue happiness using whatever means you see fit is wildly overbroad, I DO find something useful in that concept, insofar as it prompts us to say that the individual is entitled to define happiness for themselves
In other words, while "sorry, that thing you want to do in pursuit of your good life harms the community, you can't do it" is (in general) a valid reason for regulation, "I think your conception of the good life is wrong and will stop you from pursuing it for your own good" is not
That this is the genuine motivation behind anti-gay laws strikes me as obvious, and certainly susceptible to being shown in the course of a trial/legal argumentation. Could you maybe write some laws imposing duties of care around the spread of HIV that would be valid? Yeah, maybe!
I feel bad replying in the middle of what I know will be a longer reply, but I want be abundantly clear that I do not consider the discussion we having to be about constitutional law. "Liberalism" is a theory. A constitution is an attempt to put that theory into practice.
A full gun ban (or whatever law you care to consider) may be perfectly consistent or inconsistent with a specific constitution, and that has little-to-no bearing on whether or not it is liberal.
"We shouldn't do it because it is unconstitutional" and "we shouldn't do it because it is illiberal" are entirely different claims. Some illiberal laws may be constitutional, no matter how hard you try to make sure your constitution disallows illiberal laws, because that's the nature of the game.
Oh yeah this is absolutely correct. My theory of liberalism ends up recommending something very much like American-style constitutionalism, with broad majority rule and a zone of individual liberty exempted from regulation. Of course lots of people disagree with me about that!