> Because "anti-abortion/pro-life" removes a right from women. Trading the rights of a developed adult for the rights of a hypothetical future person.

Their perspective is that abortion is killing a human being. Given that, it’s entirely consistent.

> What does ancapistanism have to do with it?

Nothing, other than that I was providing some context on where I’m coming from.

> Is there a non-religious reason to be against the right to choose abortion up to 24 weeks of pregnancy?

While religion is certainly a factor for a lot of these people, this question doesn’t make sense to me. Is there a non-religious reason to be against killing any person, regardless of age?

The base difference in perspective is that the other side here believes that the fetus is a human being, with all the rights that come with it.

> Is there a non-religious reason to be against the right to choose abortion up to 24 weeks of pregnancy?

Of course there is. It's not hard to construct an argument to that effect either. For example: let's agree for the sake of argument that a newborn has moral rights, and that gametes do not. It doesn't make much sense to give the fetus moral rights only based on its physical location, therefore at some point between conception and birth the fetus gains moral rights. No matter what point n we choose, the objection "why is one day earlier any better" seems pretty persuasive. Therefore, by induction, the only point for assigning rights which can't be argued against in that way is at conception. Thus, we should disallow abortion so we aren't depriving the fetus of its rights.

I'm not saying that's a bulletproof argument. Indeed the argument doesn't even need to be correct for my point. My point is that nothing about that argument requires any religious belief whatsoever. So it is possible. I'm also quite certain that a cleverer person than I could construct a better argument which still doesn't require any religious dogma. This is an ethical topic, not a religious one. Obviously religion has a lot to say on ethics, but that's no reason to believe that secular arguments against abortion can't exist.

Well social/religious conservatives often think the child has rights even during pregnancy so it's not as simple as the mothers rights.

The libertarian view tends to much more favour the parents rights to make choices for their children if I remember correctly, and obviously favour the option where the government isn't deciding for them.