Geof Stone, who argues that it's improper for a government official to make a decision based on "his own, sectarian religious belief" (see this post for more), gives this example, which I've also seen others give (emphasis added):

[I]n what sense is it "ethical" for Mr. Bush --- acting as President of the United States -- to place his own sectarian, religious belief [about stem cell research] above the convictions of a majority of the American people and a substantial majority of both the House of Representatives and the Senate? In my judgment, this is no different from the President vetoing a law providing a subsidy to pork producers because eating pork offends his religious faith. Such a veto is an unethical and illegitimate usurpation of state authority designed to impose on all of society a particular religious faith.

But, as I noted last year, it turns out that many laws do ban the eating of various animal products, for reasons quite unrelated to "objective" matters such as human health. California voters in 1998, for instance, banned the sale of horsemeat for human consumption. Georgia law bans the sale of dogmeat for human consumption; I'm sure some other states have similar laws.

I have no reason to think that this law was motivated by religion. Rather, I suspect that most voters supported it because of their gut feel that eating horse or dog is disgusting or, in the words of one critic of eating horsemeat, "morally perverse," "a perversion of the human-animal bond." Many of the laws' backers probably didn't even think that horses had a right to life, or a right not to be eaten; the law banned only the sale of horsemeat for human consumption -- the sale of horsemeat for animal consumption is, to my knowledge, still allowed.

Both religiously motivated pork bans and the gut-feel-motivated horsemeat bans burden people's liberty to eat what they please. (Geof Stone's exact hypo, which is the denial of a subsidy to pork producers, doesn't even suffer from that problem, but I'll happily use the more troubling case of a total pork sales ban.) Both of them do so because of the unproven and unprovable views of the majority.

One can say that both are permissible, on democratic grounds. One can say that both are impermissible, on libertarian grounds. But it doesn't seem to me sound to say that (1) the pork (religiously motivated) ban is impermissible, (2) the horsemeat (disgust-motivated) ban is permissible, and (3) if it turned out that in some state the supporters of the horsemeat ban were actually motivated by a belief that it was sacrilegious to eat horse, then the horsemeat ban would become impermissible. In any event, supporters of such a distinction have some explaining to do, it seems to me.