From a reader:
Jonah, I think the point of horse theft meriting hanging in the Old West was that when you stole a man’s horse in an Arizona desert in 1870, you were effectively condemning him to death. This does not hold true of today’s gorilla poachers in Africa.
One problem with expanding (or contracting) the number of death penalty
offenses is that you need to maintain some sort of graduated punishment
system. If the penalty for rape, e.g., is the same as the penalty for murder (be that hanging or three years probation), what incentive do rapists, muggers, etc., have to leave their victims alive? Doing so only increases the likelihood that the victims will eventually testify against the perps. Of course egregious cases like that poor two-year old could be made to fall into a special “aggravated” category deserving death.