House Democrats are poised to push through a bill this week that would loosen President Bush’s restrictions on federal support of embryonic stem cell research. The bill will be opposed by legislators beholden to religious conservatives. Many are likely to cite a new study suggesting that broadly useful stem cells can be derived from amniotic fluid without destroying embryos to get them.

The new study, while certainly intriguing, in no way lessens the need to widen the array of embryonic stem cells available for research and ultimately therapy. The Democrats’ proposal is extremely modest. No embryonic stem cells could be tailor-made.

The stem cells would have to be derived only from surplus embryos that were originally created for fertility treatments and would otherwise be discarded. It deserves support from veto-proof majorities in both houses. Stem cell research holds enormouspromise, though top rsearchers say it could take a decade or more to develop useful therapies from it.

At this point, it is important to explore all approaches: using “adult” stem cells, which can grow into a very limited range of body tissues; the cells found in amniotic fluid, which may yield a broader range of tissues; and the most versatile cells of all, those derived from early human embryos.