Having 'moral status' equates to being the kind of thing it is wrong to kill. According to Elizabeth Harman, if a woman decides to have an abortion, then the fetus does not have moral status. If the mother decides not to have an abortion, then, due to the future life of that fetus, the fetus has moral status.
I have moral status. If my mother had decided to abort me, then I would not have had moral status. When I was a fetus, my mother decided not to abort me and, in virtue of that fact, I had a future life. Consequently, I had, and still have, moral status.
This is a terrible and silly argument.
First, moral status of the kind in question is not something one has accidentally. One does not have it in virtue of any fact apart from the existence of the kinds of things that have it. For any x, if x has moral status, then x has moral status at any time at which x exists. Human persons have moral status at any time at which they exist.
Second, if this is not the case, and it is the case that moral status is contingent on some external factor, then there is nothing to stop one concluding the following: I have moral status unless you decide to shoot me dead. If you decide to shoot me dead, then, in virtue of that fact, I do not have a future life and, consequently, I do not have moral status.
What Harman should do is either argue that there is some feature of the fetus that renders it lacking in moral status or some morally sufficient reason for killing a child. Though, I don't think either route works, what she proposes instead is silly and dangerous (the above looks of Harman's interviewers are appropriate in the circumstances)