I can't understand the logic of it being legal for rape and incest but illegal otherwise. Either the unborn is viewed as our equal or isn't. If it is, then this would mean punishing an innocent for what somebody else did.
I agree with you completely on this point, and think that the quick easy way most conservatives are willing to allow for the exceptions just show that their real intent is to control women's bodies, not any genuine ethical issue with the "personhood" of the fetus
You are right that any exemption contradicts the presumption of a full and equal personhood status for the fetus.
However, the anti-choicers could argue that the fetus is fully human with legal rights that prevent their killing except in extreme circumstances, but still not the complete rights a born child has, similar to how children do not actually have the same rights that adults do. Parents are given a level of control over their children akin that is closer to what is allowable towards prisoners than normal adults. Kids are not permitted to be without adult supervision, they have little rights to privacy from the parents, little rights of ownership, they can be treated in ways that would be minor assault or false imprisonment if done to an adult, they cannot vote or drink, etc..
Yet, they are still viewed as just as "human" as adults and have many rights that protect their life and welfare.
It could be argued that a fetus should be a notch below a post-birth child, and also be protected from actions (or neglect) that harms them, but if the mother being prevented from killing would likely cause severe harm to her physically or psychologically, then she would be allowed to terminate it. Note this logic could not apply to born kids because even if caring for them harms the mother, their is always the third option with them of given them to the State or someone else to care for.
Such an argument still greatly undermines the principle of individual rights, of which control over one's body is by far the most important. I'm just pointing out that legal "personhood" can be and really already is treated as a graded variable than a dichotomy.
Personally, I favor free and easily accessible abortions anytime, anywhere, for any reasons. I favor choice for principled reasons based in rights, but also favor society making abortion as easy and attractive an choice as possible, because the mother and society are better off if only fetuses that the mother has no doubts about wanting or being able care for are brought to term.
Rights are important, but they are our invention (neither god nor nature give a fuck if we have them). It is important that all people who act and interact with others in their community have rights and are forced to respect those of others. But fetuses don't meet that criteria, so "No rights for you!" It's important that once rights are granted to a person that they cannot be taken away unless the person act to forfeit them by violating the rights of others (IOW, criminal actions). But since we already give different levels of rights at different stages of development and we decide which species get them, then not giving any to a fetus until it is physically separated from the mother is a perfectly sensible thing to do, especially since rights are about being an individual and fetuses are not physically individuated from the mother.
