Well, it is inevitable that a deconstruction of which rape is legitimate and which is not, that the true goal is to ban abortions, period. Since we have waded into those waters...whatever the cause of the pregnancy, whatever one's definition of a living human deserving full rights, it comes down to this. Does the mother/womb decide for herself if she will carry the fetus to term, or does the government?
Clearly many people feel that the government should make the decision, and that it does, indeed have the right to do so. Rationalizing it on religious grounds--that are not the same for everybody, by the way--does not change the fact that it is not the person directly involved making this huge decision.
Many of us feel that she should be allowed to make that decision for herself, whatever the reason, and that to make public policy to the contrary is to diminish her personhood. Making decisions as to what happens in a woman's womb is tantamount to rape, which is where the current round of this discussion began.