What was the Due Process that protected slaves?
There was none. Non-persons, property. Don't look to the Constitution to help you.
Bad example. We were wrong to not consider persons of colour persons, just because their skin colour was different. And we corrected that mistake. The difference was that black people were capable of reason, emotion, communication, self-expression, and all of the other things that make a person a person. Regardless of what the moralists would like everyone to believe, a fetus is not. Now, the first time a fetus - not a "former fetus" mind you, but an actual fetus - expresses to us it hopes, dreams, desires, fears; once a fetus writes a poem, or a piece of music; once a fetus produces a work of art, then I will happily admit that I am wrong, and jump on the "Don't kill the fetus" bandwagon.
Until then, a fetus is not a person; it is merely a
potential person, and I will, forever, be more concerned with
actual people, than I am with
potential people. And I will not apologize for that.