The case against abortion is actually quite simple: Human beings have human rights. Human rights can only logically begin when the human being begins. Science tells us that a living, unique, whole human being begins at fertilization. Thus, abortion is an act of violence that ends the life of a developing human being. (Quote from Jonathon Van Maren’s book, The Culture War) 
All arguments for abortion simply attempt to dismantle this truth.
- They claim the pre-born are not yet human beings.