Why is it Libertarians don't support prohibition of abortion based upon the non-aggression principle? Do they see the unborn as not a real person?
I think that abortion is an area where intelligent people can disagree. That question seems to come down to the definition or perception of the beginning of life, and therefore whether the fetus should have its life protected.
There are others who believe abortion is an act of violence, but still don't think government regulation of abortion is helpful to the outcome.