The real question is not should abortion be legal, it's :
When does life begin and if there is some gap between the the formation of a zygote and what we can categorize as life, is it ok to prevent that zygote to reach that stage with out it being murder.
Blindly Religious people will 99% of the time insist life begins at conception which means they will 99% of the time view abortion as murder.
Rational people aren't so sure about the process but generally are more likely to accept the concept of abortion.
I'm pro-choice up until the point where we can call a zygote a life instead of a zygote and also in the case of danger to the mother, or rape.