Person is a legal, not biological term. In the United States on is a person at viability unless the state determines a different point in the second trimester. No first trimester embryo or fetus is a legal person. Because the state is not seeking their deaths (nor Democratic Catholic politicians) there is no negative right to life, i.e., it cannot simply be declared as a natural right. It is a positive right that must be enacted, and the states are constitutionally incapable of doing so. Only the sovereign national government can. You can argue if you want, but I am giving you the keys to the kingdom. You even have an ostesibly pro-life Congress. Go to it!