In Defenders of the Unborn, historian Daniel K. Williams asks: why did the pro-life movement last so long, even as other social conservative movements faded away?
The answer lies in the fact that pro-lifers see themselves as leading a human rights campaign. This may be blindingly obvious to those inside the movement. But many on the outside still see the fight against abortion as a crusade against sexual immorality. Williams go through the history of the pro-life cause decade by decade to show that it had its origins in liberal values of defending the weak and not conservative sexual morality.