Your statement that the only topic of the abortion debate is the religious/ideological beliefs of pro-lifers is ludicrous. Really. To claim FACTS are irrelevant and we must only consider ideology/religion devoid of facts is nonsense.
It also would be pointless debate - no different than a Protestant and a Catholic arguing of which of them is right. Belief is just that, belief. It changes when they both want their religion to be required by law.
I have no problem them believing whatever they want to. Really. If they believe abortion is wrong so be it. When it becomes a matter of legally forcing their religion? THEN WE TALK ABOUT FACTS, not religion.