Bring Back Beheading!

The Supreme Court has banned the three drug cocktail as a painful means of execution and therefore unconstitutional. My home state of California, seeking to kill people in a humane way, is moving towards a single drug method of execution. My question for both the Court and those states that still have the death penalty: Why not beheading?
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If we really think it's important to kill in a humane fashion, it's hard to beat the ax. One very quick chop, an immediate severing of the nerves in the spine, and it's all over in the only method that is close to being painless. The only reason why the United States wouldn't emulate this advanced means of death is squeamishness on the part of prison personnel. I admit that, if I were a prison guard, I would be a bit traumatized, seeing the prisoner's head plopping into a basket, and the fountain of blood squirting across the execution chamber. But what of it? In the name of humanity, shouldn't our representatives be able to stomach a little mess? Yes, beheading is the way to go. If it's really our aim to kill in a sensitive, humane fashion, than the blade is the only method of execution that guarantees a fast and painless end. And if we don't really care about the suffering of the condemned, than let's go back to the garrote! Now that's deterrent.