Monolithium's post is a good example of how some argue these issues. They take a superficially powerful assertion and they say it over and over and over. Because if someone disagrees with it they're obviously bad, so there can be no debate.
You're right, Mono, that we basically have our minds made up on this issue. But Warbler very quickly identifies the error you're making: there is the matter of what the choice is. It's not even just a matter of what is right and wrong in some personal sense, but a belief that the fetus is a human life.
walkingdork is right that calling abortion murder is not consistent with allowing exceptions for rape.
If we're going to be technical, I think many pro-life people see abortion more as manslaughter. Intent plays a big part in defining the culpability. I think many of us have a sense of the intent involved if a raped woman seeks an abortion vs a woman who had unprotected sex and doesn't want a baby right now.
I agree with walkingdork's term "potential child." Though I think the potentiality is understated by those on the pro-choice side - which I went into at length on page 2 (where I keep getting a weird offsite pw popup, btw). My position is that the embryo/fetus is undeniably a human life, though not a person. As a form of human life and a potential child that will become an actual child without some intervening event, it deserves legal protection. To me, the exceptions for rape, incest, life of the mother are about balancing other valid interests (which include physical autonomy).
We won't necessarily share moral and ethical values but at the very least, I think we can recognize and tackle what the other side is saying. What I see in Mono's post is that the life of a fetus, at best, has subjective value and at worse, is simply irrelevant. To me that is a cold and foreign view. And certainly doesn't lend itself to being challenged. I think that is the frightening part of his view, to answer his question. And to the extent that a majority accepts his view, it will prevail. However, most people do see a non-subjective worth in the life of a fetus.