Abortion Laws

I don't quite get why abortion laws being made to save fetus lives, considering that the government itself is a necessary evil of the society, having a state declare a law in the pro abortion campaign in my opinion would be somewhat disastrous. Considering the possibilites as the number of people who are not financially well, the number of people who are mentally well.
All these reasons can be a choice, you cannot enforce morality into action, something that in general people usually don't understand.