It's not a fiction that fetuses aren't people, they have nothing which I wish to associate with person-hood. Convince me that fetuses are people.
"person" has an interesting etymology. Latin persona originally meant a character in a drama or a mask. The word persona has a pretty interesting history stretching back to the Medieval Philosophers. There are several definitions in any given dictionary. It's a very interesting word. It's philosophical meaning is different from its legal meaning though the two meanings are also connected in various ways.
I just think it makes more sense to call fetuses legal persons than it does to call corporations legal persons. Given a choice between the two I would choose fetuses. I side with the fetuses against the corporations in this definitional jihad. If you had to choose just one, which would it be? I'm guessing you would refuse to answer, and that's fine.
In Law a person is simply a human or organization with legal rights and duties. The law can call anything a legal person as the case of the corporations points out. There were sound reasons for this legal fiction though I would have made up a new word for corporate personhood. The 14th amendment was clearly about natural persons.
A natural person is a man, woman, or child, in distinction from a corporation. I want to add zygotes, embryos and fetuses (OH MY!). I think the 14th amendment should be applied to the unborn. However, I am a little worried that the embryos may hijack the elections with all their campaign finance money.
How about this: If we cannot agree that a zygotes, embryos and fetuses (Oh MY!) should be considered a natural persons, then can we at least agree that they are human beings?