The Roman Catholic is worst. It construed conception as starting from the meeting of the sperm and egg. St. Augustine and Aquinas were not even sure when is the start of hominization of humans but our great bishops were very confirmed on their stance. Whereas the medical field says that conception starts upon fertilization or when the zygote had been formed. Morowitz & Trefil even said that formation of cerebral cortex which at the last term of pregnancy was the likely start of being human (capable of acting as a unit or as a person).
This belief in the beginning of humanity or being human is very crucial in the debate because the RC offer no exceptions in case of abortion: whether you were raped, or there was a threat to your health, or there was fetal impairment. No woman is exempted: a woman who aborts a fetus is a criminal, "worse than a murderer" says our parish priest.
Thus, the realpolitik of the abortion debate is being molded primarily by the Church, not the presidency, not the legislative or the judiciary.
So what is the chance of passing a law on comprehensive RH? Perhaps, it would not come in our lifetime. But changing the 1987 Constitution by striking this Art 2, Sec 12 on the "right of the unborn" might be the first step...