Abortion for or against it?

Obama is 100% for abortion he thinks it should be legal in the U.S.A. He thinks that even if the people get pregnant on purpose and then suddenly change their mind its okay to get an abortion.
McCain thinks that it shouldn't be legal. Regardless of the circumstances unless it rape McCain thinks that it shouldn't be legal.
Now honestly, in my opinion abortion is just wrong. You kill an innocent child every time you or anyone else in that case gets an abortion. I don't see why Obama is for abortion, if you ask me if people are interested enough in making the child or don't think long enough to use protection then they should just take the responsibility of caring or at least having the child and putting him/her up for adoption.
I'm not sure what I would do in that position myself but I am hoping that I don't make the decision to have an abortion, (if I ever decide to have kids, much less get pregnant by accident!).