Christian loons who support the death penalty.

[Jehanne]

I would say perhaps that's an oversimplification of the scenario.  Many people who are mentally ill can still discern right from wrong.  That's why the accused are afforded fair trial, along with psych evals from a qualified professional if they pursue that line of defense.  If a defendant was deemed mentally impaired to the degree of not understanding their actions then I would agree that the death penalty is not an appropriate punishment in that circumstance.

What about the mentally retarded, which the Supreme Court ruled is cruel and unusual, yet Texas sees fit to execute them anyway?

http://www.alternet.org/civil-liberties/...sabled-man

One must wonder why the Supreme Court did not intervene?  Probably, because they consider themselves to be a court of appeal and not of fact-finding, which they leave to the lower courts.