Apparently some people think that if Christian conservatives cannot justify their opposition to an idea via a consistent argument, it cannot be repugnant. Here's William Saletan on whether we should clone Neanderthals:
If we do this Church's way [using a chimp mother], I don't see how conservatives can object. They didn't object last year when scientists announced the cloning of rhesus macaque embryos. That, too, was the creation of nonhuman primate life. Follow the human lineage three branches beyond the primate order, and the rhesus macaques are still with us. Follow the human line two more branches, and the chimps are still with us. One more branch, and you're down to us and the Neanderthals. If it's OK to clone a macaque and a chimp, it's pretty hard to explain why, at that last fork in the road, you're forbidden to clone a Neanderthal.
How about because it is (almost) the last fork? Neanderthals were probably almost as intelligent as us, and no longer exist. What would it be like for the cloned creature, alone and an object of curiosity and experimentation in an alien world? Isaac Asimov tried to answer that question in his short story "The ugly little boy" (Wikipedia summary; the original is probably not online, at least not legally). It is one of the most moving short stories I have ever read.
For that matter, I also dislike experimentation on chimps, for reasons that neither Christian conservatives nor people like Saletan are likely to fathom. Unlike people who believe in a Biblical view of the world, it seems to me -- and anyone familiar with modern biology should agree -- that there is no sharp dividing line between humans and other primates, or between primates and other mammals. We draw the lines arbitrarily: what creatures we may eat, what creatures we may experiment on. Chimps and other primates are, it seems to me, too close to humans for comfort.
This framing of the ethics debate in terms of fundamentalist Christianity has problems on both sides. Everyone in the west, apparently, implicitly accepts the Biblical position that humans are different from other animals, and animals exist solely to meet our needs. Neanderthals were not the same species as us; ergo, we may do as we like with them. Non-Biblical religions, in particular Buddhism and Jainism, would not argue such a position.
And if it is OK to do this with Neanderthals, how about humans of lower intelligence, or humans of other races? We have been there and don't want to go again.