Yeah, I know the bit about "cruel and unusual punishment", but from reading the descriptions of the latest executions, I suspect that it isn't cruel at all.
Anyone with medical training has probably read the descriptions of the executions and thought, "It's just agonal breathing". I have seen it a couple of times and it preceded death.
Essentially, it is a body's last gasps where a patient opens their mouth very wide and appears to be taking in large quantities of air. Actually, these gasps are not effective. I suspect the gasps seen by witnesses were only agonal breaths... of a dying person.
So, the condemned patient is shot up with vast quantities of euphoria-inducing drugs (hydromorphone) until they are unconscious. The patient essentially succumbs to respiratory depression... where the normal autonomic functions of the body, such as breathing and heart pumping cease.
Cruel and unusual? I personally don't think so. Sure, there are namby-pamby bleeding hearts out there that decry outrage.
I'd rather go that way than hanging, firing squad, and electrocution. You know how a shock can be traumatizing... I'd HATE to be killed by electrocution... man, THAT is cruel in my mind.