As regards sodomy, pornography, masturbation, etc.: these laws were on the books, and enforced [though clearly not uniformly], which was the premise of my thesis of “how such laws can be justified”. Apparently, the lawmakers found sufficient justification.
It’s not as irrelevant as you imply: your remark that “the State has the power to regulate commerce” could work as a justification for regulating a poker game if cash changes hands, just as ieasily as it could be used to regulate sex. Your exclusion of child pornography actually supports the point being made, it simply reduces its scope [allowing certain classes and disallowing other classes does not disprove the the government’s predilection; if anything, it tends to support it]
[BTW: one person argued that “I don’t have a license, so I can serve liquor in my home as I wish”. This is false. You don’t need a license, because the law says so. The law could just as equally well say that you can consume it legally, but be jailed for giving it to anyone else, even in your own home. In fact, for some substances, the law says exactly that. Just try serving up your month’s supply of Percocet at your next party with a DEA agent around]
Also INAL, but AFAIK, the First Amendment [“Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.”] is used to support the right to publish pornography, not view it. AFAIK, the Supreme Court still allows local laws based on "prevailing local standards’ to establish what pornography is licit or illicit to possess or sell, under what circumstances, in each local jurisidiction – just as, even after the repeal of the 18th Amendment [Prohibition], local communities can and do declare themselves ‘dry’ by local law.
Despite the Supreme Court ruling, such laws remain in force in other jurisidictions (Foreign nations and the US military). Perhaps I should have been clearer that the main body of my post applied to government in general.
Here in the US, the UCMJ [Universal Code of Military Justice] prohibits sexual behaviors that are legal for civillians. (Indeed, it’s common for prosecutable offenses to vary between different branches at the same station.) Though the enforcement of such policies is a political hot potato, and a policy of relative non-enforcement is in force, there is a strong stark refusal to remove the laws, and they have never been ruled invalid (merely politically incorrect). If I were seking a case of masturbation (etc.) being prosecuted today, I’d look to military cases first.
Since no explicit Constitutional justification was ever offered to support the implicit assumption that “I can do as I wish in my own home, so long as it doesn’t affect others,” this is not a matter of constitutional law. I was simply pointing out that governments (local and national) find ready justification for laws that are as or more invasive than banning your friendly Friday night poker game.
Perhaps I should have stated more directly that that implicit assumption doesn’t carry much legal weight (or demanded a cite that it did). It can be weighed in deliberations, but you’d really have to stretch to find it in the Constitution. Many people have tried to justify “a man’s home is his castle” using (e.g.) the 3rd and 4th Ammendments, the extrapolated ‘right to privacy’ of Roe v. Wade, and other established law, but thus far, AFAIK, no court has ever upheld any principle that precludes government from making such laws. The government allows itself the right to control commerce or the right to regulate voluntary sharing of legally obtained controlled substances, etc, even inside your house.
I’m not even saying that’s a bad thing.