Actually, solitary confinement is a great idea.
I was in jail several time (Operation Resuce related) and while I never experienced rape, I did have a few confrontations which I managed to handle.
What struck me about my weeks in jail was how people would hook up to commit crimes together on the outside. People were planning to get into the drug business together, etc. It was like a convention of criminals. Not that jail is a great place to be, but once these people are in, it's not all that bad -- 3 hots and a cot. They play chess, checkers, work out, talk, etc. It's not a place which makes criminals not want to return.
It made me a believer in solitary confinement. People won't want to come back if they are alone 23 hours of the day.
So, now, do you put scarce tax money into schools or into building single cells for every prisoner in America?