I just don't understand what a real compromise position would look like. To me, the question is whether a fetus is a human or not. If yes, abortion is horrific in almost every instance. That's why I think it's much more difficult for the pro-life side to compromise. I can certainly understand, and in certain cases would myself advocate, a call for the attempt to reduce the number of abortions, completely absent from defining a fetus as human. Whereas once you say that abortion is murder, I don't understand any morally sufficient compromise position. And it's both pro-life boilerplate, and explicitly stated in the Republican party platform, that the GOPs stance is that a fetus is a human. I know some people argue that you can think a fetus is a person and still have a compromise position. I just think that stance, frankly, is kind of loony, when you really consider the consequences of that thinking.
Except that we live in a pluralistic democracy, not under the rule of a philosopher-king, and the fact that compromises between factions with vastly different views on fetal humanity will inevitably result in philosophically-muddled legal regimes isn't a reason to prevent, via judicial fiat, those compromises from taking shape. Here's an (admittedly imperfect) analogy. Suppose you believe, as some people do, that health care is a universal human right, and that any death that could have prevented by a single-payer system is a blot on the human rights record of the country that allows it to happen. But then suppose you live in a democracy with no publicly-funded health care at all, and with clear majorities opposed to using public funds to guarantee universal health care - but with majorities that do seem amenable to some sort of very basic guarantee of health care to the aged, the poor, and the very young. Would it be "kind of loony" to compromise your firm belief in health care as a basic human right by supporting the creation of Medicare and Medicaid? Of course not: Any serious advocate of health care as a human right would take that compromise in a heartbeat, given the alternative, even though it's in some sense "morally insufficient" to what they'd like to see the government be doing. And likewise, I think most serious pro-lifers would welcome a legal compromise that moves the ball some distance toward a regime that's consistent with their view on feticide, even if the result is philosophically muddled (it's not as if the Roe-Casey regime is a model of philosophical rigor in the first place), and doesn't deliver full protection to the unborn.