> In fact, I think most supposedly 'pro life' states carve out such exceptions?

I think a lot of them are explicitly not carving out any exceptions. But for some reason, it's really hard to get accurate acces to this information.

> Does it really take 20-24 weeks to realize and act upon this? Keep in mind I'm asking about where the line is placed, not about whether or not abortion should be permissible

I wasn't discussing what should or shouldn't be. Simply explaining why there's no easy way to gather consensus on where to draw the line.

In practice, in most places that allow abortions, there are already limits in at what point you can get an abortion. This is a common compromise between pro-life and pro-choice. I think only two states used to allow abortions at any point for any reason, all others had reasonable limits with carve outs for exceptions.

If you look at the statistics, an incredibly small number of abortions are made beyond the first few weeks. There's a lot of secrecy in the details, but it's likely those made after the first few weeks are cases of medical complications, unforseen life altering surprises (death of the father, financial bankruptcy), or were due to inability to actually get an abortion sooner, long waiting times, social stigma, etc.

> I disagree. Science tells us very precisely what kind of life is being disposed of at every stage of pregnancy

Things are a lot fuzzier than you claim.

Sometimes you can't even tell that there are two fetuses until the 20 week mark.

It's not that there's nothing you can observe, but what observations you consider important to use as a criteria on a cutoff is arbitrary. A beating heart? What does that mean? We can grow a beating heart in-lab, is that life?

A 6 months old baby? Is it conscious? Self-aware? You can try to see if it acts differently when seeing a photo of itself versus that of other babies, what does that truly tell you?

People can't agree on if a lobster feels pain when boiled alive...

That's what I mean by that you can't just appeal to science, you have to apply an arbitrary judgement to what science is able to observe.

> My point was that setting the cutoff at "viability outside the womb" is equally as extreme and just as likely to be motivated by political expediency, in the opposing direction

Yes, that's my point as well. I was arguing to your other point:

> Shouldn't it be something more reasonable like "has a relatively developed brain", "can experience pain", "shows early signs of consciousness", "has major organs", "is a recognizably bipedal/human lifeform", etc? [...] grounded in anything scientific or morally conscionable

My point is that none of these are any more or less reasonable. They're all based on some arbitrary rational we've agreed too.

If you're curious though, it's not "viability in the womb", it's actually "fetal viability", and it refers to the complete opposite, which is viability of the fetus to survive outside of the womb.

> Fetal viability is the ability of a human fetus to survive outside the uterus. Medical viability is generally considered to be between 23 and 24 weeks gestational age. Viability depends upon factors such as birth weight, gestational age, and the availability of advanced medical care

The argument goes, if the fetus can now survive without the carrier, on "its own", aka inside advanced medical incubating machines and under advanced medical supervision, the fetus is therefore no longer dependent on the carrier, that means instead of giving an abortion, you could remove the fetus and see if it'll live. The mother can therefore "end" her pragnency without resorting to aborting it, she can simply choose to accelerate the delivery instead.

Now some people think this is also a good criteria for the threshold to be considered alive, that you can survive on your own, independently, detached from a host. You could argue that it's reasonable to say life begins when you can survive as an independent organism (and maybe being dependent on machines and medical care counts as well).