A society cannot run if it tolerates the killing of the innocent. Nor can it run if it tolerates stealing. These are basic aspects of human life, and are not exclusively tied to the beliefs of any one religious denomination. You do not have to be Catholic or religious at all to understand that killing the innocent is wrong. The woman should decide.
Abortion is the killing of a baby.
Abortion is not an issue for politicians to decide. Thomas Jefferson stated that the only legitimate object of good government is the care, and not the destruction, of its citizens. Abortion kills 1.6 million babies a year, and that is a serious, public issue involving human rights and human lives. It therefore involves those who are responsible for public policy. Government has a duty to protect its people, not to pretend that they aren't people at all.