[Ross] Responding to my earlier post, Matt Y. writes that yes, legislatures can regulate some conduct that takes place within a person's body, but that they can only do so in the context of health-and-safety regulations, not to protect fetal life (unless said life counts as a person under the Fourteenth Amendment, in which case the point is moot anyway):
... The common thread tying together the sort of regulations Ross is citing here is a public health rationale. I don't think anyone would dispute the constitutional right of congress to prohibit or curtail the use of a genuinely dangerous abortion procedure -- regulations aimed at protecting the health of pregnant women. Abortion regulations that lack health exemptions, however, can hardly be said to be public health measures. Alternatively, one could try to see abortion bans as a kind of commercial regulation -- like a rule that you can't have a liquor store next to a school, or zoning in general. But I find it hard to see how this sort of rationale could support banning the provision of a class of medical services throughout an entire state or country.
What's more, anything along these lines would be offered in bad faith. Abortion opponents don't oppose abortion rights because they think such rights are bad for the health of pregnant women. Nor do they oppose legal abortion because they think it's bad land use policy. They oppose it because they think fetuses have moral rights that ought to be instantiated as legal rights. This, however, leads to the conclusion that courts should require abortion bans, just as the SCOTUS wouldn't let a state pass a law saying "murder is illegal unless the person you kill is over 73." Either way, it'll be decided by judges.
I guess I don't think of laws banning prostitution, or even laws banning drugs, primarily as public health regulations - I think of them as morals legislation, outlawing practices that the majority considers sufficiently offensive to human dignity to deserve an outright ban. And in this context, I don't see why killing one's unborn offspring, even if the offspring isn't a legal person and the crime therefore isn't the same as murder, shouldn't be something that the state has an interest in regulating on moral grounds. (We have laws against animal cruelty, for instance, even though animals aren't legal "persons.")
This, incidentally, is why so many conservatives hated on Lawrence v. Texas - not because it did away with sodomy laws, but because Anthony Kennedy's majority opinion seemed to hint that any and all morals legislation was effectively unconstitutional. That was the substance of Scalia's dissent, which warned that laws against everything from prostitution to obscenity would be threatened by the decision. For now, though, that threat hasn't been fulfilled - and as long as morals legislation in general is still safe from Supreme Court override, there's no reason a state or Congress shoudn't be able to restrict abortion (in a post-Roe world, that is) even without claiming legal personhood for the fetus.