we already did. The 14th amendment authorizes the federal government to prevent states from depriving any person of life or liberty without due process. Should the unborn have less rights than black people? Should the unborn have less rights than illegal aliens? No. Do states have the power to deprive the unborn of their right to life? No. Not any more than they have the power to deprive you of your guns.
That is finding an emanation in a penumbra. State it plain. Get an Amendment.