Here is my view (not arguing anyone else) - but abortion isn't killing a baby. Exfoliating your skin scrapes off 100's of cells. I mean, that shows how small a cell is. Who says the baby's life would be good anyway? Who says it would develop normally anyway? Who says its foster parents, if that's its future, will be good? I mean seriously - the anti-abortion "killing baby" stance IS mostly a Christian view, which is fine, but from a secular point of view, it's just too hard for me to see how it's immoral. And furthermore, if people think it's immoral, let it be legal, and those that don't want abortions don't have to get them, and those that do have the option.
Seriously, destroying a zygote isn't killing a baby - it can't DO anything, it's merely potential life. Honestly, when people are ready for babies, they'll have the babies. Until then, if they have unprotected sex, they should be able to do whatever they want.