I am unaware of the administration attempting to obstruct use of placental/umbilical or adult-derived stem cells; while the latter don't seem as promising yet, from what I understand the former have enormous potential and are available in sufficient quantities to actually do some good.
Beyond the moral difficulties of harvesting stem cells from embryos which were conceived for exactly that purpose [if any therapies based on such cells take off, that's exactly what would happen] there are serious questions about the 'reliability' of such cells. Stem cells taken from the placenta/umbilical cord of a healthy baby can be considered to be pretty well "genetically pre-screened"; if the baby is apparently healthy, there can't be anything too much wrong with it genetically. On the other hand, a significant portion of embryos have very serious genetic defects which would prevent them from developing into a healthy baby. Trying to use stem cells from such an embryo may have disastrous consequences.
Maybe, but that is not a reason to not do the research.