His comments are so confusing I think you might be right that on a personal level he is Pro-Life. However, he doesn't want the govt involved in the decision of the mother. IOW, the same argument a lot of other politicians make, "I'm Pro-Life but the govt shouldn't be involved."
I think this explains why he wouldn't sign the Pro-Life pledge.
That’s not what he said on the radio yesterday. He took a pro-life position.