Here is the real deal on abortion policy: activists on both sides of the abortion debate understand yet rarely acknowledge that a critical plurality of Americans don't much like abortion but care a whole lot about when and why abortions occur. That plurality position, especially from the point of view of anti-abortion activists, is morally and metaphysically incoherent; if a fertilized ovum is a full human being with an immortal soul, and putative constitutional rights, then it doesn't much matter when or why it is aborted; the result is homicide.
The RTL movement's focus over the last decade on restricting late-term abortions has thus been morally dishonest, but politically smart. But they've missed the connection between "when" and "why" concerns. Much of the popular support for so-called "partial-birth" abortion bans has flowed from a common-sense concern that unwanted pregnancies could and should have been avoided in the first place through birth-control methods that many RTL activists view as abortifacients, or through earlier-term clinical abortions. In other words, from a RTL point-of-view, the prevailing popular opinion is that women seeking late-term abortions should have instead committed homicide earlier, through either pharmaceutical or surgical means.
But there's still another disconnect between RTL and popular opinion that goes beyond "when" questions: "why" questions. While public opinion research on this subject is terribly insufficient, I think it's plain that Americans care as much about why as when abortions are undertaken. Abortion-as-birth-control is unpopular (again, excepting the RTL presumption that many birth-control methods actually involve abortions). So, too, are "convenience" abortions: those undertaken for "lifestyle" reasons. But short of mandatory sodium pentathol doses for applicants for abortion services, it's very hard to legislate against the kinds of abortions that a majority of Americans would actually want to prohibit.
A couple of points. Philosophically speaking, it may be true that there's a gulf between pro-lifers and some inhabitants of the mushy middle on the when/why issue Kilgore identifies: Pro-lifers obviously wouldn't endorse a "she should have aborted earlier!" theory of late-term abortions, but perhaps many Americans who support some abortion restrictions would. I'm not certain, though, whether this matters in practice when it comes to imagining legislative compromises that might be possible in a non-Roe/Casey world. Some Americans, myself included, would support a ban on second-trimester abortions because they favor any restrictions that expand the protections afforded to the unborn; others might support such a ban because they think unwanted pregnancies should be disposed of in the first trimester or not at all. But the end result would be the same - a shift toward a philosophically unstable but politically plausible middle ground on abortion - and of such inconsistencies are successful coalitions and compromises made.
It's harder, for the reasons Kilgore lays out, to envision a compromise based on the "why" issue - but perhaps not as impossible as he imagines. You could imagine, for instance, an America in which second-trimester abortions are straightforwardly illegal, and a series of surmountable impediments to abortion - for instance, a requirement that women obtain pre-abortion counseling that actively discourages the procedure - are thrown up in the first trimester, as they are in some Western European countries. (A commenter in the Schwenkler thread recommends Mary Ann Glendon's Abortion and Divorce in Western Law on this subject, and I second the motion.) Again, you could imagine pro-lifers supporting such measures on the grounds that they bias the law in a pro-life direction, and Kilgore's "when/why" pro-choicers supporting them on the grounds that they'd presumably help discourage abortions of convenience without actually preventing abortions of necessity. (In a similar "no abortions of convenience" vein, you could also imagine a law that banned repeat abortion - which is to say, almost half of all abortions in the U.S. - though obviously enforcement would be extremely difficult.)
As you might expect, given the foregoing, I don't see anything "morally dishonest," as Kilgore puts it, about the pro-life approach to partial-birth abortion. Yes, of course, the pro-life movement's goals extend well beyond restricting one particularly barbaric third-trimester procedure. But you take restrictions - and the opportunities to highlight the inhumanity of abortion - where you can get them, and there's no reason why pro-lifers have to preface every single argument they make against partial-birth abortion with oh, and by the way, you know we want most other forms of abortion banned as well. (It's not like the movement's goals are some big secret!) Consider: Would it have been "morally dishonest" for opponents of slavery to promote, say, laws prohibiting the flogging or castration of slaves, even though such laws didn't actually do away with slavery? Surely not - and even if such laws didn't directly free anyone from bondage, they would have been a plausible way of highlighting the basic inhumanity involved in owning slaves. And so it is with partial-birth abortion. All abortions involve the dismemberment and destruction of a growing human life; it's just that the partial-birth procedure makes the thing more explicit, and more horrifying. And even if all that a ban does is call attention to what's involved, more generally, in "terminating a pregnancy," that's a pro-life goal worth pursuing.
I think Kilgore is on stronger ground, though, with his critical references to pro-life attacks on the morning-after pill and (especially) the birth-control pill. My views on this subject are colored by the fact that I don't find the argument that either pill should be classified as an abortifacent particularly convincing, and I don't think the pro-life movement is helping its cause by blurring the lines between actual abortifacents, like RU-486, which are taken with the intent to abort an embryo, and contraceptives that are designed to prevent conception, but may have the secondary effect of preventing implantations on rare occasions. (At the moment, moreover, the evidence that this ever actually happens is relatively thin.) I think a pro-life movement that expends a great deal of energy campaigning against the pill is essentially assuming the permanence of Roe and Casey, and placing its hopes in a much broader cultural transformation that seems extremely unlikely at the present pass. It's behaving like a Church, in a sense, rather than a political movement, and I already have a Church: The point of the pro-life movement, as I see it, is to seek discrete and plausible political change, not to seek a revolution in the post-Sexual Revolution human heart.