I support a ban on all forms of embryonic cloning, and I support the president’s policy on stem cell research, which balances the moral significance of human embryos with the potential for medical advancement.

Embryonic stem cells have the special ability to develop into every type of cell in the human body. Their medical potential may include treatments for Parkinson's disease, diabetes, heart disease and other ailments. Supporters say the bill awaiting Senate consideration limits funding to stem cells from those embryos that would be discarded by fertility clinics in any event because they are unneeded by couples.

Opponents say the research amounts to destruction of human life. The policy Mr. Bush enunciated in August 2001 permitted funding for research on those stem-cell lines that existed at that point. To create embryonic stem cells for research, a stem-cell line must be created from the inner cell mass of a week-old embryo. Embryonic stem cells can grow and divide indefinitely and can be distributed to researchers.

Another officially undecided Republican is Sen. Norm Coleman of Minnesota. Though Mr. Coleman has a strong right-to-life voting record, his state boasts a large biomedical industry, the Mayo Clinic and a top stem-cell research facility at the University of Minnesota. Some of those biomedical interests worry that failure to overturn Mr. Bush's policy will push stem-cell research overseas or to states such as California, which recently passed a $3 billion bond issue to conduct such research.