That is exactly why I used that term, because the people whose god is SCIENCE! suddenly get metaphysical and talk about a concept of "person" when discussing murdering babies.
Apparently you are so certain about this metaphysical concept, you are willing to take the chance you might be wrong at the cost of 50+ million lives.
They aren't babies. Babies are what they are once they're born, before that they're a fetus. As for 'personhood', It's not a metaphysical concept. The defining line can be shifted a bit, but it involves a thinking being that acts upon it's experiences and such. A fetus isn't a person. Heck, even a newborn isn't really a person yet, but I'm willing to extend the protection to them in order to be sure we're protecting people.
I'm 'so certain' because I've already pushed the protection past the definition.
I suppose you don't consider the costs of denying abortion(and in some cases, meaningful sex ed that actually reduces teen pregnancy), do you? Increased taxes, increased crime, increased number of children in broken homes...
Look, I think there's too much abortion today, but I don't support getting rid of it. That way lies South America and their tendency to try women who have a miscarriage with having had an abortion, putting them in prison for murder.