The Senate Democrats are sending out a fact sheet on stem cells that shows how the debate is beginning to get away from them.

The fact sheet quotes President Bush talking up “alternative stem cell research,” in particular Sen. Norm Coleman’s legislation. The Democrats’ response begins: “Fact: Most scientists agree: adult stem cells do not have the same potential as embryonic stem cells.” It continues in that vein.

But Bush wasn’t talking about adult stem cells. People who want to knock the potential of adult stem cell research say that adult stem cells aren’t pluripotent–that they don’t have the mutability of embryonic stem cells. But Coleman’s legislation specifically concerns pluripotent stem cells, not adult stem cells. For example, it would fund research on the reprogramming of adult somatic cells into pluripotent stem cells.

When the debate pitted adult stem cells against embryonic stem cells, the proponents of the latter had a decent argument on the strictly scientific point. They’re losing that edge as other alternatives proliferate, and their response seems to be just to repeat the old talking points.