Some people here have apparently not heard of pulling out.
Abortion is a touchy issue. Stupid, irresponsible people shouldn't have sex and risk pregnancy, but they do. If abortion were illegal, would it be less of a crime for these people to have kids, not care for them, neglect them, and multiply the whole cycle? What happens to all of these kids?
If abortion is legal, does it provide a tool for people to use it as contraception rather than an emergency safeguard? Does it encourage further irresponsible behavior?
There's truth to every side of the debate. There's no clear answer because everyone feels differently.
I do think it's extremely naive to limit sex to purely reproductive purposes. That risk is always there, but people don't have sex just to have babies. They do it for plenty of other reasons, whether to express love or to just bust a nut.
I'll personally never understand why people feel so strongly about abortion, one way or another. When it comes down it is a personal thing. Abortion makes for nice debate but in the grander scheme of things it's not a huge deal.