While eugenics plays a part in their thinking, the big reasons that Democrats/liberals/progressive fight for abortion is because of their haughtiness and arrogance and misguided sense of protection for their young. Fewer people means they can have the beach or forest trail all to themselves. Fewer people their children’s age means that there is less competition for their kids. Their kids might be able to make the basketball team after all! Democrats really are completely self-centered. Even their social programs are just means of holding other people down.
Undoubtedly that's part of her motive ~ more for her own, and less of the rest of us.