Dear Scholle:
First, you should understand that most Americans very much support the IDEA of the death penalty. That is to say, for our worst criminals if they are proven guilty and there are no mitigating circumstances (excuses), it is appropriate to execute them. If done quickly and "fairly," the death penalty not only rids our society of the worst of criminals (rather than keeping them alive in prison for 50-60 years, at taxpayers' expense), but it serves as an example to other potential criminals that they will be executed if caught and convicted. But alas, it doesn't often work that way.
Note also that the U.S. Constitution sanctions the death penalty in at least two places. Both the Fifth and the Fourteenth Amendments refer to the government "depriving a citizen of life" (that is, executing them), and stating that doing so requires "due process of law," which refers to having a trial, conviction, and so on. So if the government has a trial and does things properly, the Constitution says that the government has the right to execute them.
So, theoretically, in order to outlaw the death penalty, it would be necessary to amend the Constitution. But as with slavery 150 years ago, there is a large and vocal portion of the population that would like to eliminate the death penalty (despite the wishes of the majority), in any way that they can, even knowing that they could never get enough support for a constitutional amendment to eliminate it. Their strategies are basically the following:
They look at the 8th Amendment to the Constitution that prohibits "cruel and unusual punishments." At the time when it was passed, the authors were referring to physical torture, starvation, and things of that nature. Anti-death penalty partisans claim that the "cruel and unusual" language evolves over time, as society's standards evolve. Indeed, in 1791, when the Eighth Amendment was ratified, flogging (whipping) was a common punishment for many crimes, and the penalty for stealing a horse was execution. Obviously, contemporary Americans would be horrified to impose such penalties now, and they are generally considered to be unconstitutional, as unnecessarily "cruel and unusual." So the argument goes that the death penalty has now become "cruel and unusual," so should implicitly be prohibited. But the U.S. Supreme Court has never fully accepted this argument.
The second attack on the death penalty is a practical one. The U.S. Supreme Court over the years has simply made it incredibly difficult to execute someone. The trial court must go through many procedural steps to convict someone of a capital crime, there are mandatory appeals through the courts, appeals can be in both the state courts (where most of them are convicted) and the Federal courts on numerous grounds. The result is that in most states, it takes 8-10 years to execute someone, even if everything goes "smoothly."
Then, any governor can stop an execution any time he wants, and for any reason (or no reason at all). He can simply decline to sign the death warrant, without which the execution cannot proceed. Most American states have dozens of people who are sitting in prisons on "Death Row," and waiting to be executed. Other than in Texas, more "capital criminals" (people sentenced to death) die of old age or disease than are actually executed.
Thus, the death penalty is quite rare, and even non-existent in many states, despite the fact that the general population would prefer to have it available for the worst criminals. To be specific for a moment, we now have a U.S. military officer who opened fire on, and killed several soldiers in an internal terrorist attack a few years ago, and I would bet that 80% of the U.S. population would not only support his execution, but would gladly fire the shot into his despicable brain to accomplish the deed.
Death penalty opponents constantly spread the idea that any given person convicted of a capital offense COULD BE INNOCENT(!), and if so, the State would be guilty of MURDER! This puts some people off, and of course there have been a very few cases where people on Death Row have been vindicated. But despite a hundred years of trying, they have NEVER found a single case of someone being executed who did not in fact commit the crime for which he was convicted. Not a single case.
Hope this little essay is some help.
Mit freundlichen Gruessen von Pennsylvania (USA)
Dave