Possibly the most interesting bill of rights provision is the Eighth Amendment, which guarantees that prisoners of the United States will not be subject to "cruel or unusual" punishment. When this clause was approved by the states, a federal statute calling for the hanging of pirates, traitors, counterfeiters, mutineers, and jailbreakers was already on the books. We cannot pretend that the framers of it meant to encompass all death as a cruel and unusual punishment. Yet this exactly the provision under which attacks on the death penalty are supported.
Harold Pollack over at the Reality-Based Community discusses the policy arguments behind the Death Penalty with plenty of common sense and restraint. The mere fact that the death penalty elicits a great deal of emotion from disinterested observers makes us wonder if it isn't an 'unusual' or 'cruel' punishment under a modern frame of reference. Americans intuit the largeness of the principle involved in being a country that puts its citizens to death, and there are plenty of partisans on both sides. While many people smarter than me have delved deep into whether the policy is an effective crime deterrent (it isn't), or is required by some larger ethical code (read: Leviathan), there is still quite a lot of territory in the is-it-worthwhile-as-a-constitutional-value debate
So does such a reading of the 8th Amendment--necessary for the defense of US survival and commercial interests beyond the borders of teh states--support a state's killing of a citizen? First of all, let us note that the power to punish criminals was until recently a local or state capability. The barest definition of the Police Power--the domain into which federal oversight could not be supported because it was so central to the organization of a sovereign political body--obviously includes the ability to define criminal behavior, prevent it, or punish it. A citizen would have to directly challenge the federal government with force for a federal death penalty to be issued. Murder at the high seas or piracy, or the counterfeiting of federal money would all threaten the commercial viability of the sovereign. These were the only instances in which federal power would put a man or woman to death, and it had nothing to do with the states.
Like so many things, this changed with adoption of the 14th Amendment. The Due Process clause, which guarantees to every citizen of the US basic criminal procedure protections at the very least, clothed convicts of state courts with the same rights as those in federal courts. In Furman v. Georgia, the Supreme Court, in a fractious decision, temporarily halted all death penalties in the United States. The basis of 3 opinions (two justices held that the death penalty was cruel and unusual simply because it had become rare enough) was that the death penalty was used unequally when its application was left up to a Jury. Most states quickly rewrote their most objectionable death penalty laws, cranking up the state apparatus for remedial homicide in about a decade.
As the "evolving standards of decency" keep changing, we should constantly reevaluate our society's taste for the death penalty, both in light of our internal preferences as well as those of the international community. If the United States is exceptional among developed nations in pursuing capital punishment against its criminals, does that fact alone make execution cruel or unusual? The degree to which we look to international legal norms to answer our constitutional questions will be a mounting question in the years to come, especially as countries whose constitutions we helped to write stake out different constitutional territory.