America is very much about bundles of belief. You have to buy into the left or right wing completely.
On most things, I'm an extreme liberal and I don't have any particular religious belief.
But I have great difficulty with abortion, though many of my friends are ardent pro-choicers.
I simply can't agree with the sentiment that life begins at birth. There's no magical event which starts the baby feeling pain at birth. A baby can feel pain in the womb past a certain point. But no-one knows exactly what that point is. I can understand people setting 'viability' as a milestone point, but I'm not even convinced by that - viability gets lower and lower with medical technology.
For a long time, we believed that newborns could not feel pain. Circumcision and surgery without an anaesthetic were considered ok.
I also believe that babies need protecting. Using the 'life starts at birth' argument, it would be ok to stop the heart of a term baby as long as it has not been born. If the umbilical cord was cut, that would be considered infanticide.
I don't know how you make a cut-off point for abortion. It's rather arbitrary. I also don't honestly know what the law should be on abortion. My feeling is that it isn't really justifiable because it is the ending of a life (not a potential life) and I can't reconcile that feeling. It doesn't make me popular, but I have to be honest about it.
I can't subscribe to the pro-choice viewpoint that a foetus is not worth anything until it is separate from the mother.
I don't actively campaign against abortion. But it's tough... you wouldn't stand by while someone killed a born baby and in my heart, I can't see a clear, definable difference between a born and unborn baby so if I accept abortion (particularly late term), I feel I am standing by while something awful is happen. But that's pretty much what I do.