Gallup released an analysis today focusing on the relationship between religion and opinions on abortion. It is not exactly full of surprises, but here is the conclusion:
[K]nowing an individual's frequency of church attendance helps predict his or her attitude toward abortion, above and beyond what can be predicted by knowing that individual's partisan affiliation. Republicans who attend church regularly are the most likely to be anti-abortion, while Democrats who seldom or never attend church are the least likely to be anti-abortion. Both variables are important in understanding the nature of abortion attitudes in America today.
The full article is available here.