Here's the thing about abortion as a political issue, that most republicans tend to miss - a lot of people think it's wrong. If they catch a poll question along the lines of "do you think abortion is murder" or "do you think abortion is morally wrong" - they'll say yes.

However, many of those same people will turn around and describe themselves as pro-choice, especially in rape/health cases. It's a situation where just because people personally believe the act is wrong, that doesn't mean they want the government making that call for them. "Personally pro-life and politically pro-choice" or "safe, legal, and rare" are sweepingly common stances on that issue. That's why strong pro-life candidates tend to go down in flames.