@engineer,
You are asking me to speculate on a belief system that isn't mine (I believe that abortion should be legal and available for anyone to some stage of development where we define the fetus as "viable").
Consider someone who feels that abortion is taking a life and is therefore morally troubling. They might also feel that it is not taking a human life and is therefore not immoral to the point of murder. There are plenty of morally troubling behaviors that we regulate but allow exceptions.
Let me push back on the idea that this is about two distinct opinions rather than a spectrum of opinion.
Most Americans (I believe) believe that there is a point, considerably before the due date, where abortion is no longer permissible. What if a woman just before labor wants to end the pregnancy.
Are you really willing to take the other extreme that a woman has the right over her body up to delivery? Or are you actually somewhere in the middle (along with Chai's friend)?
I am also interested in your opinion of abortion for gender selection, or genetic profiling (e.g. having lots of pregnancies and choosing the ones with athletic genes).