So if we illegalize abortion, it would therefore mean worse forms of abortion will be committed? So we must make it lawful, since people are doing it anyway? And thus, make it a much more effective, clean, and less messy process? Murder is murder no matter how you put it in terms of much more sterilized or less sterilized environments. 

The idea of protecting life at all stages as best as one can, is not a numbers game. Just saying abortion has dropped is not the purpose. It is to enact laws when one can to protect that human life to the same equal dignity and rights afforded them as anyone else has. Their circumstance or factor of set characteristics of birth (i.e. handicap, sick, born in poverty, etc.) do not dictate if they should be welcome to those rights as human beings. 

People who are of marginal circumstances or born with a certain skin quality and color are no less welcome to those rights because they were born as slaves. For those are self-evident and God endowed.