In a 1992 study, Carson and his colleagues from Johns Hopkins used fetal tissue to better understand how the human brain develops. But in the wake of the Planned Parenthood videos, the presidential candidate has called fetal tissue research “disturbing.” Ben Carson, a Johns Hopkins neurosurgeon and Republican presidential candidate, previously did research using human fetal tissue. In the wake of the hidden-camera videos showing Planned Parenthood doctors discussing how to provide aborted fetuses to scientific researchers, Carson has told Fox News that the benefits of this research have been “overpromised” and “under-delivered.” Late on Wednesday, an OB/GYN and science...