You have to understand the “pro-lifers,” who are also libertarians. Libertarianism doesn’t condone the criminal act of murder, and such people believe any abortion, at any stage of pregnancy, is murder. So intrusive invasions of a woman’s body with ultrasounds are justified as a way to prevent the crime of murder from occurring, in their minds.

My belief is that, until a fetus is viable outside of its mother’s womb, it is not a human life, it is a POTENTIAL human life, and is still part of the mother’s body, to do with as she sees fit. And viability occurs around the 2/3 point of a pregnancy, in my understanding.