While I agree with you Scott, I think you are ignoring the main problem for the pro lifers. If they really believe that abortion is murder, then they have to support it being made unlawful.

Self interest a motive for many, but arguments about why it is desirable or necessary just will never get there. Murder can be desirable, convenient, and life-enhancing for others in some cases too.

You must prove that it is not murder. To do that you have to show that the object being removed is not a human life which inevitably is endowed with an immortal soul? Science cannot prove a negative.

The problem is that many religions are pro life and people cannot be argued out of irrational beliefs through reason. Even a total understanding of the biology will not come close to addressing the religious belief that the object is a human, and consequently the act is murder.

That is why we have reached an eternal impasse, and this subject has degraded to an election stunt.