So here's my position. I'm pro-choice, but in a limited way. I think first trimester abortions should be entirely legal, but later should be restricted to cases of incest or rape or major fetal abnormality.
Why? That question was answered by my younger daughter. She's a vegetarian, but wasn't at one point a strict vegetarian. I asked he how she decided she can eat something. She said "if it doesn't have a face".
That may seem a very superficial criterion. But it's not. If you spend any time in the preemie ward, you see lots of kids born long before 9 months. A child born at 22 weeks is (barely) viable, but more importantly for my point, looks like a baby. Meanwhile, at the other end a cell or a fertilized zygote doesn't look in the least like a child. What leads on to protect one and not the other is that we innately recognize preemies as human; and humans are recognized by their faces. We're trying to avoid killing babies that we recognize as unambiguously human beings.
Of course, this position satisfies neither of the polarized extremes. That's probably in its favor.