I understand what you are saying, but IMO it is equally emotional once you start talking about when "humanness" happens, or when "soul infusion" begins and other off the wall conjecture. It's okay because it is a "clump of cells", so are you BTW, all human life from fully developed adult on his way to dementia, to the pre-birth baby minutes before delivery are just a "clump of cells".Whenever people talk about the fetus, it's in terms of potential; it is not in terms of fully realized.
It's interesting you bring up emotionalism. To me, this is one area where emotional appeals lie almost strictly with one side, with claims of liberals wanting to murder babies, and kill those on life support, and just kill, kill, kill....
The emotion runs strong in the debate because both sides are unwilling to take a different look, to go in a totally new direction that sees both the rights of the mother and understands that life is a bit more precious than trash at the same time. It doesn't have to be "fully human" at that moment, there is no emotion involved, just a recognition that this is more than just a "parasite" as I've heard it described. Seriously, both sides use emotive language and have in this thread and both sides attempt to use religion to justify their stance, magic-men and their dead representatives (Saints) have been mentioned in this particular thread to promote the "pro-abortion" position.