demonstrates how far removed we are from standards of morality as seen by the rest of the world. I've done some research on the death penalty in Brazil, which was abolished soon after the abolition of slavery in 1888. It was used primarily for slaves who killed their masters, and 19th century jurists saw it as a stain on the reputation of Brazil as a civilized nation. That was 140 yrs ago. The US still hasn't reached that level.
The guillotine was seen as more humane at the time of the French Revolution. Its association with the Reign of Terror is not easily forgotten. Besides, who wants to pick up the heads and clean up the blood? I see no way that SCOTUS would ever approve such a method as in keeping with the 8th Amendment (which in my view the death penalty itself violates.)
People who justify the death penalty by pointing to the atrocity of the crimes of the condemned miss the point. Our penal system and forms of punishment reflect who we are as a society. Ours is among the worst in the world--one of only a handful of countries that still uses the death penalty, the highest prison population in the world, and atrocious conditions within prisons. It can hardly be a surprise that we are among the most violent societies on earth (measured through the homicide rate and our state of perpetual war) when we as a people are comfortable with state-sanctioned death. Violence begets violence, and the US has become highly adept at perpetuating it.
(Someone will come along and say violent crime rates are down. That is result of demographic factors, not because the death penalty functions as a deterrent).