Here is a link to an animated slide show that demonstrates what the process for extracting the stem cells from an embryo and SCNT involves. Many people worry that those of us who are opposed to ESCR and SCNT only do so because we are hopelessly ignorant or idealogical. If they can educate us we will be more receptive to this field of research.
So look at the slide with the blastocyst sectioned to illustrate the trophoblast and the inner cell mass. They may fairly ask me, "Are you saying that mass, that clump of cells, is a human being deserving of rights? Does it look human? Does it possess the qualities that we associate with persons? It is a clump of cells!"
Here I think we hit a snag in differing world views. As I understand the natural rights that I have, they are unalienable and endowed to me by my Creator. My stance is "illogical" to the naturalist because all rights are assigned through government. The naturalist is asking me if I bestow rights on that clump of cells.
The answer is obviously not. I believe that all human beings have a natural right to life that neither I nor our government gives them. I believe that the lump of cells is a human being in the very early stages of development. I fail to see how the number of cells, cognitive ability, or relative size of an individual determines how I am to morally treat them as human beings.
So, yes. I do in fact look at the inner cell mass and the trophoblast and say that it is a human being. I have read several intelligent and articulate people who disagree with that belief, understood their arguments, and walked away from the experience still not convinced that the embryo is anything other than a human being. Many people have made clever arguments that it is not, but I have yet to hear much in the way of what exactly constitutes a human being if we disqualify the embryo.