You are, of course, offering up a scientific reasoning, which is good. However, scientists are divided on whether a fetus is truly a living human being.
But the scientific arguments are not what the religious right (fake right) is offering up for their arguments. They are basing their arguments against abortion solely on what they consider to be the Word of God. So, in that context, let us see what God himself has to say about the subject.
As you can see, a man was fully formed, but did not become a living soul until he took his first breath. After he became a living soul, he was named Adam. Until he took his first breath, he was not a person.
If that is not enough to convince you, then perhaps this will be:
As you can see, the punishment for causing a woman to abort her fetus is a fine of amount to be dermined by the judges. So, if abortion is murder, as the Religious right (fake right) claims, then why isnt God demanding a life, as he does in the case of murder? That is because, according to the Word of God, a fetus is NOT a person.
As you can see, the religious right (fake right) is going against God's word on this issue. When you combine their advocacy for things non living with their callous disregard for the living (as in the women and children who are murdered each and every day in Iraq), then any reasonable person, as well as any truly non-hypocritical religious person, can only conclude that the religious right (fake right) is blaspheming God.
But Jesus did say that, before his second coming, there would be a great falling away from the faith, where doctrines of devils would be preached instead of God's word.