It has always struck me that the dominant image of pro-life held by pro-choice and the image of pro-choice held by pro-life is that of a single-issue essentializing position. Neither is really correct, but the rhetoric has so distorted communication and understanding that groups which agree on at least 80% of the problems and 50% of the solutions (The Foster quote which you highlighted could have come from either side, at least the either sides I know) can't work together on them.
There have been fledgling attempts to work together. In the 1990s, the Common Ground Network for Life and Choice (I loved the name) flourished in many cities. In 1996, the Philadelphia Inquirer reported on the successful cooperation of pro-life and pro-choice activists in the battle-ground city of Buffalo. And in 1999, Naomi Wolf and Frederica Mathewes-Green (two women whose work I have assigned my students), shared this brief dialogue in Sojourners.
I like what Naomi Wolf wrote about her own experiences in dialogue with pro-lifers:
When you open yourself to the kinds of change that common ground creates, you lose aspects of your identity that you have been clinging to. I had parts of my ego stripped away from me. It's very humbling. I had to face the fact that I might have been wrong all of this time, and that people I felt united with in solidarity might be wrong. The other painful thing I had to face was that I owed an apology. I needed to ask forgiveness of the wrong I had done.
This is where one more principle about common ground thinking can work. I don't agree with Frederica about policy, but I'll remember for the rest of my life what happened when I apologized to the pro-life people in the room at a common ground conference. I thought I would lose everything by asking forgiveness and, of course—no surprise to you, big surprise to me—I gained a sense of freedom. I felt truly liberated in a way that all that rigid us-them liberationist rhetoric I had labored under all my life had never freed me.
Naomi is still on the "other side". But bless her heart, she gets it. She really gets it. As a pro-lifer in the overwhelmingly pro-choice academy, I have to remember to try and practice exactly the kind of humility and openness that Wolf talks about here. It's danged hard. But if we all started by apologizing to the other side for the ways in which we stereotype them (and I am as guilty as anyone else, even though I have been on both sides), we'd be well on our way to common -- and higher -- ground.