death penalty

http://news.yahoo.com/s/ap/20080625/ap_on_el_pr/obama_child_rape_case

I'm finding myself generally in agreement with Obama when things like human rights come up. At least with the things he says he's in favor of.
Going through some ethical debates, generally the only crime that people come away with unable to possibly defend is rape. Murder can occasionally be willed away by circumstances (self-defence, war, etc).. Rape doesn't have extenuating circumstances that make it a defensible act. In other words, rape is the highest form of criminal act (though I suppose rape-murder is ahead of it). Basically the sense is this, murder can be rather cruel, unusual, heinous or whatever term is added to it. But the victim generally shares one characteristic: they're all dead. Rape (without murder) shares other characteristics. But generally the act itself destroys another person's life. Levels of trust, intimacy, sexual interest, emotional states, all of these can be severely diminished. The recovery process can be painful and time-consuming, if at all possible. In the case of a younger person, we may be dealing with many years worth of recovery, extensive therapy, and a number of damaged relationships or self-damaging relations as a cost imposed on the victim of the crime.

Granted, people who are dead don't get that opportunity, death occurs for all people regardless of whether they're killed or maimed by assailants. We perceive and punish the act of unjustly killing others because it is naturally 'wrong', in the sense that a society with rampant killing doesn't function. But we also have to come to grips with death naturally. We are not required or bound to a similar fate regarding rape. No one is so required by their existence to be raped as we are required by our existence to be mortal.

So here's the problem: the court decision doesn't sound like it offered an explanation as to what specifically about the 'cruel and unusual' punishment amendment applied to the child rape death penalty cases. I'm not sure that it does because we have death penalty cases involving other crimes (crimes less heinous than rape ethically speaking, say gang killings over drug money). I'm also in agreement here with Obama, it's never a deterrent.. but it is a disposal system of sorts.

I'd like to know what exactly was wrong with the idea that rape (w/o murder) is worthy of a death penalty statute. What does a crime committed have to do to apply to the constitutional standard? Because I can think of very few circumstances that I would deem as higher qualifiers, things more damaging to the social fabric, than these cases as described. (incidentally, I might put some of the priests up on death row as well for the child molestation cases rather than paying fines, when the evidence supports it).