For one thing, we must be clear about what we're talking about. "Stem cell research" is a very vaguely defined thing. The question is, what kind of stem cells will be used in this research? Will we destroy human embryos to harvest their stem cells (which may not yield any greater scientific advancements than are promised by other types of stem cells)? That's the question.
Yes I believe we should use human embryo's which is okay with me because I don't believe life begins until the fetus gets a heartbeat and that's not until 8 weeks into the pregnancy.