Being a recently licensed attorney, I can totally speak on this!
Not really, but I will anyway.
Legally, the difference here is the matter of one sentence. That sentence deals with when you consider life to begin. I don't know it exactly because it's not my area of expertise. However, I do believe in being Pro-Choice.
But, for the sake of this argument, I'll break out the papers... so let's look at the legal definition(s) of life:
1. The aggregate of the animal functions which resist a state of death.
-- Well, this doesn't tell us much as far as Abortion is concerned... it's too vague.
2. The state of animated beings, while they possess the power of feeling and motion. It commences in contemplation of law generally as soon as the infant is able to stir in the mother's womb
-- This is the definition that is most evenly presented and the least controversial (and when you see the next one you'll find out why). According to this, that's somewhere in the 2nd Trimester (correct me if I'm wrong, I don't have children and I'm not a physiologist). Thus, if it is destroying life, that means that abortion would be legal somewhere in the first few months. However, we get to the next definition...
3. For many purposes, however, life is considered as begun from the moment of conception in ventre sa mere. Vide Foetus. But in order to acquire and transfer civil rights the child must be born alive. Whether a child is born alive, is to be ascertained from certain signs which are always attendant upon life. The fact of the child's crying is the most certain. There may be a certain motion in a new born infant which may last even for hours, and yet there may not be complete life. It seems that in order to commence life the child must be born with the ability to breathe, and must actually have breathed.
-- This is where the real debate comes in. The language presented in this definition, having been gathered from more than one source, contradicts itself in some places. Now, this also opens up another question: do you consider life a civil right or a natural right? Is it a right at all? Granted most people see it as the same thing but we as researchers and judicial scientists have to constantly amend these things. In our world, being born is not the same thing as being alive.
Anyway, the entire point is that legally it's a gray area. There's nothing we can do about that. This will never be settled, no matter what you think, because in the end, it's only your opinion.