Keep in mind, that one doesn’t have to be a Christian or any sort of religious person to find abortion to be wrong and harmful to person and society and state.
Same for homosexuality and all sexual practices outside of adult, monogamous, lifetime, male-female, sexual activity.
One merely has to love his fellow man, his neighbor, and want the best for society and state to share the so-called “Christian” views on marriage, sexuality, and abortion.
Too often, in public forums, secularists immediately jump to Christianity as the means and rationale for berating those who see the flaws in abortion and perverse sexuality, and Christians themselves advance Christianity and God as the rationale for seeing abortion and perverse sexuality as flawed.
We Christians should always point to our faith and to God’s word, but we don’t need to always do so when entering debates in public forums with secularists hostile to Christianity.
The most hardened atheist could and should side with Christian public policy views on abortion and marriage and sexuality.
I think that's delusional. If, as the hardened atheist believes, people are simply the result of random processes in a closed universe, then the only conceivable morality is complete hedonism: whatever is good for the atheist is moral, and murdering anybody else that gets in the way is just good business. You have to take their philosophy all the way to where it leads. It leads to mass murder, genocide, and infanticide, which are all things they support.
Natural reason, guided by Natural Law, can find the reasonable worth of every commandment of the Moral Code.
Supernatural Law confirms what was already put in our hearts ---instinctually, if you will --- by God: "Thou Shalt Not Kill."