Can somebody explain to me what the argument for being pro-life is?

Personally, I'm not entirely comfortable with abortion. Ideally very child could be born and grow up in a loving household free from poverty and the like...but this isn't a perfect world, and I certainly wouldn't use the law to force women to carry pregnancies they don't want to have. Probably the best thing pro-lifers could do is put their money where their mouth is, and form institutions that make raising children a more viable option for women, and tend to the welfare of the child. But wait, oh, they don't want poor people to have kids either. Don't have kids you can't afford, but don't have abortions, and don't look for birth control to be in your insurance package. Now that I think about it, it is interesting how much control of sex and reproduction is politicized.