"pro-lifers respect the bodily autonomy of dead people more than live women"
This is a popular pro-choice talking point, but it's not true; the whole "bodily autonomy" argument is just a mask for the personhood argument, because it ignores the bodily autonomy of the fetus.
The basic pro-choice argument here is that people shouldn't be forced to go through with pregnancy, even if it does mean ending a human life, because it would violate the pregnant person's bodily autonomy to have their organs used to support another human life without their consent.
However, if there are 2 parties involved, you also don't have the right to deliberately violate *someone else's* bodily autonomy. Consider for a moment a situation that's pretty unsympathetic to the second party: the urban legend where you wake up in a bathtub full of ice, missing a kidney. Your bodily autonomy has been violated. That sucks. But once you're patched up, if you then go out and kill the person who stole your kidney to take it back, as sympathetic as we might be, you'll *still* be arrested for murder. You violated *their* bodily autonomy and two wrongs don't make a right.
Now consider the more-closely-analogous case of adult conjoined twins, where (through no fault or deliberate action on either part) they can't be separated in such a way that both will live. Twin A goes to the doctor and says "Hey, it's pissing me off that Twin B is using my organs without my consent. I want you to kill him and detach him so I can have sole use of my body." Twin B says "Wow, I understand your frustration at being put into this situation, but I would really prefer to remain alive and try to make the best of it." There's no way your average doctor is going to grant Twin A's request, because being killed would violate Twin B's bodily autonomy against their express wishes.
In cases where we can agree that everyone involved is an adult who can speak for themselves and therefore a person with rights, it's pretty clear that "bodily autonomy" isn't a license to kill another person.
So back to pregnancy. If the fetus isn't a person with rights, then abortion should be a routine procedure like having a wart or a cyst removed. It should be legal solely on the basis that there are absolutely no grounds for outlawing it; there's no need to bring bodily autonomy into it. If the fetus *is* a person with rights, then there's *also* no reason to bring up bodily autonomy, because it also applies to the fetus - they can't force you to give up your organs to *save* someone else, but neither can you *kill* someone else to preserve your organs.
So we're back to personhood.
The basic pro-choice argument here is that people shouldn't be forced to go through with pregnancy, even if it does mean ending a human life, because it would violate the pregnant person's bodily autonomy to have their organs used to support another human life without their consent.
However, if there are 2 parties involved, you also don't have the right to deliberately violate *someone else's* bodily autonomy. Consider for a moment a situation that's pretty unsympathetic to the second party: the urban legend where you wake up in a bathtub full of ice, missing a kidney. Your bodily autonomy has been violated. That sucks. But once you're patched up, if you then go out and kill the person who stole your kidney to take it back, as sympathetic as we might be, you'll *still* be arrested for murder. You violated *their* bodily autonomy and two wrongs don't make a right.
Now consider the more-closely-analogous case of adult conjoined twins, where (through no fault or deliberate action on either part) they can't be separated in such a way that both will live. Twin A goes to the doctor and says "Hey, it's pissing me off that Twin B is using my organs without my consent. I want you to kill him and detach him so I can have sole use of my body." Twin B says "Wow, I understand your frustration at being put into this situation, but I would really prefer to remain alive and try to make the best of it." There's no way your average doctor is going to grant Twin A's request, because being killed would violate Twin B's bodily autonomy against their express wishes.
In cases where we can agree that everyone involved is an adult who can speak for themselves and therefore a person with rights, it's pretty clear that "bodily autonomy" isn't a license to kill another person.
So back to pregnancy. If the fetus isn't a person with rights, then abortion should be a routine procedure like having a wart or a cyst removed. It should be legal solely on the basis that there are absolutely no grounds for outlawing it; there's no need to bring bodily autonomy into it. If the fetus *is* a person with rights, then there's *also* no reason to bring up bodily autonomy, because it also applies to the fetus - they can't force you to give up your organs to *save* someone else, but neither can you *kill* someone else to preserve your organs.
So we're back to personhood.