I have no idea where the notion that the anti-abortion hardliners are in it for the demographics comes from. Well, something similar does exist, e.g. the Quiverfull movement, but they're pretty negligible compared to the bulk of anti-abortion advocates.
Ah, I don't think I made myself clear since we're citing Quiverfull here, let me explain:
My comment was a response to Heliostorm's idea that abortion is virtue signalling, that by logical implication means it has to be in reference to politicians, as voters are virtue signalling for who exactly to that extent? Unless it's then for a "who wants to be a good Christian contest", but arguably not many people are good at doing that, so that would seem like a self refuting interpretation of events from my perspective, guess it could be semi done psychologically if you're cherry picking, but people like that don't tend to be devout.
So that put into play, we're looking at politicians here. Some might have strong religious motivations in relation to abortion, that is certainly true, but seeing as only a segment of the Republican Party are in it for abortion, then we can expect the politicians in support to quasi represent that in their own numbers, not that is an 100% accurate metric of things, but does so for now in this case. If only a segment of the parties supporters are in it for it, then why do all the Republican politicians seem to vote in line with it? Likely they're mostly doing it for their constituents more then strong personal beliefs, which is admittedly the obvious here, as politicians always do that to some extent. Even people like Sanders have gone for that tactical route in some circumstances, as much as his supporters like to play him off as always sticking to the same views. Not that I think that's necessarily a bad thing, as if the other side are legit harmful or at least you think they are, then it often becomes a matter of moral considerations and balancing good/evil to do so.
My point being that when applied to politicians, there's a long term motive for it, as well as a short term virtue signalling one. Certainly not the largest motive, but it does subtly apply. However I might be overestimating the intellectual capacity of the Republican Party here, as I don't get the impression from their policies that some of them are that bright.
If one comes from a worldview with non-consequentialist morality, I don't think an appeal to effectiveness would be very convincing against the prohibition in itself (at best, to revise it). That's probably what it comes down to, though the Alabama law is remarkable in its utterly biting the bullet on the consequences. That used to be a moral puzzle against anti-abortionists: if abortion is murder of children, what moral sense do exceptions on rape and incest actually make? So according to Alabama, it's just flat wrong.
That it alienates a bunch of people, to the point of many anti-abortion advocates being very unhappy with it and its utter political ineptitude, is another issue. It's simply too dumb to not be honest, which makes it highly implausible that much consideration has gone into it besides drinking the kool-aid on the logical consequences of the core moral claim.
Not very knowledgeable in philosophy like you, so I'm probably going to put stuff with existing counter arguments forward, but I'll bite.
Non consequential 100% is rather...nonsensical in itself as a position? I mean taken to extremes, you can start arguing that you didn't murder someone, you just pulled a trigger after pointing a gun, like there has to be some consequences or in effect there is going to be none, because that's literally the nature of reality. But lets ignore that and say there's some type of logically and consistent ethical system, let us call it x, that means it's wrong in the style we brought up above and so handwave that issue away.
Then I guess we go to the problem that pushing for banning something is in itself consequential, it's not like the anti abortion people are doing abortions themselves, like what sense does engaging in a consequentialist act and engaging in political opposition against it do? That's not waving a wand, it's pushing in an overall direction and that direction isn't working, then why do it?
And I agree it doesn't make sense if it's the murder of children, without going into the line of reasoning that different people are worth more then others, which might be popular with a certain segment of the GOP (lol), but that's no means a majority of them. I guess some anti abortion people even though they think as such on the surface, subconsciously don't actually think that as human beings tend to display a higher level of altruism and empathy towards living people then featuses.
If I had to ponder myself, a good logical argument I can see for that ethical system would be that even though a fetus isn't as important as a full blown human being, it's still of some value and should be classed in line with intelligent animals like elephants or dogs. It thus being wrong to kill them for no serious reason, but in emergencies humans take priority...I don't think they go for that one though, as that'd also be an argument for vegetarianism and I don't see many vegetarian anti abortion people.
I guess it's more the logical consequence of politics. One side wants something, the other wants something. The other use a certain argument lots and lots against the first, so the first basically stick up a bill, which gets what they want 99% of the time and kills the ammo of their opponents, heh. That pushes the equilibrium towards that discourse position in the long run.