Rather than there being a line sitting in isolation, I think there is a spectrum of viewpoints, and the position of the line is determined by the point on the spectrum where there is a balance of fervor on either side.
In other words, if you can get a sufficient majority of voters to declare that partial-birth abortion is an abomination, then you have a chance to make it illegal (no matter what the judges say). Within that spectrum of pro-life opinion, you may have some who are OK with first trimester abortion, and some who think that women who get first trimester abortions should be imprisoned, but as long as a majority can agree that they all think that partial-birth abortion should be banned, then that's all that counts.
Conversely, if you have a majority which is fine with first-trimester abortion, or anti-implantation methods like the morning-after pill or IUD devices, then you will have difficulty in restricting those methods.
Progress on the issue all comes down to changing the culture, to shifting the spectrum of opinion, and thus where the line is drawn.
Where I seem to differ is that you can’t have a spectrum on a binary issue. One can not be semi preggers, nor can one partially kill their child.
I catch hell for seeing many things in black and white. But many things ARE black and white. There is alive/dead. There is Lib/Conservative. There is dark/light. And it is a waste of time to engage in the philosophy of why black is black/white is white. It serves only to draw out a given issue to avoid a line/call.
Here’s the logic as I see it. You have a live breathing child or a dead child called medical waste in the bottom of a garbage can. Abortion OR not at any stage results in one OR...OR...OR the other. There is no graded curve of anything.
One cannot define a ‘living cell’ as not being alive and have it make sense. A human cemm destened to be a fetus will not then grow into a Porsche or a gopher. There is one potential outcome (assuming a normal term pregnancy). A live human child.
Or there is so called medical waste.
Nothing between to discuss, entertain, contemplate or philosophize. Nothing. Opinions people may hold are opinions. Facts are what they are. People need to start thinking about facts instead of pondering the opinions of whoever.