Amanda Marcotte has a great post up at Pandagon: Theocratic or pro-choice: Not much middle ground between them
Basically, a blogger called The Raving
Atheist recently converted to Christianity (as Marcotte predicted 2 years ago, though perhaps he did this as a prank) after years of trying to find secular justification for his anti-abortion arguments. Amanda makes some great points about how there really is no rational secular argument against legal abortion.
Check it out!