SurveyUSA has an interesting study out where they asked people if they identified as pro-life, pro-choice or were unsure. You can click on each state to see some interesting breakdowns at the state level.
Couple of things that I noticed, mostly doing comparisons between California (a very liberal state I've lived in) and Texas (the fairly conservative state I now live in.)
In Texas, young people are more pro-life than middle aged people. In California, the young people are the least pro-life. However, in California 5% fewer young people are pro-choice than middle aged people. Those five percent list themselves as "not sure".
In both states, people who never attend church are overwhelmingly pro-choice, while those who attend church "regularly" are majority pro-life -- though in CA it's a slim majority (51% to 36% with 12% undecided). In TX, the number of pro-choice church attenders is only slightly lower (34%) but the number of undecideds is much lower (only 5%) with the extra people going into the pro-life column. It almost makes it look as if aprox 35% of church-goers are determined to be pro-choice no matter what they hear from the pulpit or the wider culture, but in a more conservative state fewer religious people fall back on "don't know".
In both states, people who describe themselves as "conservative" are more universally pro-life than people who identify themselves as Republicans. Similarly people who describe themselves as "liberal" are more overwhelmingly pro-choice than people who identify themselves as Democrats.
"Whites" are more pro-life than "blacks", "Hispanics" or "others". I assume that trend would break down if you normalized for religious fervor and income level, but the survey doesn't seem to have done that.
In California men are more pro-choice than women, while in Texas equal percentages of both men and women identify as "pro-choice" but more men than women identify as "pro-life". (More women than men fall into the "not sure" category.)
I'm not sure what it all means, but it's definitely all interesting.