Separation of church and state is definitely an issue, so they shouldn't be quoting the Bible. However, you don't have to be Christian to agree that killing another human being is bad, and should be illegal. Some people think that abortion of particularly developed fetuses is murder. This doesn't need to be a religious issue necessarily. People can be pro-life and completely scientific at the same time. One thing isn't exclusive to the other. Pro-life doesn't necessarily mean you are religious at all..