You still haven't explained why you switched from fetuses to babies.
Anyways, since you asked for it, I'll requote your response to my no-brain clone analogy:
If it was living than it is deserves the same rights you and I have. But it is completely unlikely that it would be alive. Or even if it was "living" it would be unlikely that you could count it as a living being. As it would require a brain to react to stimuli within one's environment.
I will even make it easy for you and break it down.
1) The cells of the clone are living, and will remain so as long as the conditions of a fully functioning human body can be upkept. That means food, oxygen, etc., and all of these things can be recreated easily using machines (heart-lung, IV, and so forth) and ARE recreated quite regularly in surgical operations... or did you just expect the clone to start breathing on it's own?
These cells will go on dividing and growing and dying just like they would anywhere else. Except in this case, there is NO BRAIN.
2.) This is the same condition that an embryo in the first trimester is in. The cells of the embryo are living, and will remain so as long as the proper conditions are met (nourishment, oxygen, etc), all of which are provided by the mother, another living being that just happens to be all of our machines wrapped up into one package.
... Except THERE IS NO BRAIN. The brain doesn't start to develop until late in the embryonic stage, and only begins to resemble a human brain when the first trimester is already complete.
I would like to remind you at this point that my recommended cut-off point for abortions is the end of the first trimester.
3.) You said that, while the clone might be "alive," it wouldn't count as a living being because it would have to have a brain so it could "react to stimuli." Well, what kind of reaction are we talking about? Do you mean that you'd expect the clone to defend itself if I started attacking it with a stick? No, it won't because that kind of reaction would require a brain to coordinate things. An embryo certainly won't fight back if I hit it with a stick.
Then you bring up the point of "injecting a virus" to provoke a reactions. Well, you've admitted it yourself, that the embryo relies on the mother for immunities, so any immune system that would be fighting off the virus would belong to the mother, since it's the mother's blood and antibodies flowing through the embryo at this stage. In fact, during the entire time a baby is in the womb, it's hooked up to the mother's circulator system! Your "embryo reaction" isn't really the embryo's reaction afterall; it is the mother's. The embryo is renting those blood cells, dude. (Here's a good link for some more detailed information: http://www.wikipedia.org/wiki/Fetus
Anyways, the embryo will fight the virus using the mother's borrowed immune system, and since the clone is hooked up to all the shizzy, it's blood is pumping fine and it's getting all the energy and nourishment it needs, so its immune system is working. Remember, a lot of organs are controlled by the autonomic nervous system, too, and that all operates independent of the brain (Want proof? Command your kidneys to stop working... can't do it, huh?)
So, where does that leave us... we have two clumps of cells with NO BRAINS relying on something else to keep them alive. They can react to internal events, but there's nothing that happens externally.
4.) Now we have arrived at the rights issue. If the clone were alive, then you said it would have rights... but you say that it's unlikely the clone itself counts as alive, so therefore there are no rights. There's no brain for thought to occur in, and therefore, no caring (which you define as "nothing more than chemical signals sent from one portion of the brain to the other, causing a reaction") so we can harvest the organs for our own uses all we want and no one will accuse us of murdering anyone because the clone was never truly alive to be violated to begin with.
Now how is this any different from an embryo in the first trimester? It is just a smaller clump of cells with human DNA, and there's no brain for thoughts or caring.
"Oh! But the individual cells have brains and those brains might care!"
Well, Raven, that's an interesting theory and I encourage you to conduct research in that area of science, but since there is no scientific evidence to corroborate your theory, it remains unproven and you must rely purely on philosophy and abstractions to explain it.
Fact: The embryo is performing cellular actions independant of the mother. Thus the embryo is independant. Fact: The embryo must receive certain basic needs from the mother. Thus the embryo is reliant. As such the embryo is an independant being separate from the mother, but still reliant on the mother.
FACT: Where I come from, if you remove one element (mommy) from a system and that causes some other element (cell growth) to stop, those elements are hardly independent. It is a symbiotic relationship.
And even then, assuming your argument is correct for a moment, do you consider you skin to be an independent part of you? It's really growing independently (you can't tell your skin to grow or not grow) and its just getting nourishment from you.
Besides, you fail to explain how a fetus's reliance on the mother makes it more alive than the clone with no brain.