IMHO, I do not believe that the founding fathers would have included the prohibition against cruel and unusual punishment in the Bill of Rights if they had realized that it would prevent pedophile murderers from being drawn, hung and quartered.
Whatever the founders meant by the phrase "cruel and unusual punishment" it certainly did not mean the death penalty should be barred for a variety of crimes. The founders could not have imagined that later generations would allow that clause to be used in arguments against any death penalty for murderers, and I'd be stunned if our founders would have hesitated to recommend the death penalty for child molesters, if they could have imagined the plague of perverts that we face today. Here's the publisher's blurb for a liberal's history of the death penalty in America:
http://www.hup.harvard.edu/catalog/BANDEA.html
"In the seventeenth and eighteenth centuries, the penalty was standard for a laundry list of crimes--from adultery to murder, from arson to stealing horses. Hangings were public events, staged before audiences numbering in the thousands, attended by women and men, young and old, black and white alike. Early on, the gruesome spectacle had explicitly religious purposes--an event replete with sermons, confessions, and last minute penitence--to promote the salvation of both the condemned and the crowd."