Russell Moore has a fantastic article on this topic at his site – http://www.russellmoore.com/2013/01/03/is-the-pro-life-cause-winning/
Here is an excerpt:
I’m afraid the same is true on the individual level. A feminist leader once said that most Americans are pro-life with three exceptions: rape, incest, and “my situation.” When the teenage daughter is pregnant, the theory is abandoned and bloodthirsty pragmatism rules. I fear this feminist is all too right.
Pharaoh was pro-immigrant until the Israelites threatened what he wanted. The first Herod Administration was pro-Messiah until the actual Messiah threatened his throne. The second Herod Administration was fine with desert prophets until one meddled with his “adult entertainment.” Lots of people are pro-life and pro-child until the lives of children become personally inconvenient.