It is more than just our laws. The 8th amendment to constitution protects prisoners' against cruel and usually treatment. In todays world, the failure to provide food, shelter, reasonable protection of of the lives of prisoners would certainly qualify as cruel and unusually treatment. One thing to keep in mind is half of those in prison today will be out in 5 years and I doubt we really want to turn them into blood thirsty beast.
We need to take a fresh look at our criminal justice system. Both Leftists and Rightists can find a lot wrong with it. (Leftists don't like the plea bargaining system, which sees people pleading guilty because of the promise of a shorter sentence. Rightists don't like the shorer sentences.)
What we have to first establish is that the criminal justice system should protect, first of all, law-abiding people. It doesn't do this very well now.
One thing we need to establish is whether any program of 'rehabilitation' works. I assert that, for most criminals, for most situations, it doesn't.
What 'works' is keeping criminals locked up for a very long time -- at a minimum, until they're in their 40s, when the propensity for violent behavior seems to decline. So we need a 'one strike and you're out' program.
Then we need to have a long look at ways of dealing with the 'causes of crime'. I believe growing up in the inner-city ghetto and going to a typical government school is a huge factor in 'causing' crime. It's an environment with a depraved culture.
We should consider ways to counter this. (For example, school choice. And what about state-run military academies, out in the countryside. Get those kids out of the horrible peer-pressure, where excelling academically is seen as 'acting white', and is punished.)
AND ... America needs a massive infra-structure program, centered on preparing for the coming big war.
We need to study how the Swiss, Chinese, and Israelis do their building codes, how they plan for evacuation of cities, how they make preparations for dealing with the aftermath of a big war and mass casualties, mass homelessness, etc. And then do likewise.
This would create a lot of jobs. Pay for it with higher taxes, not with more borrowing.
Close down a couple of hundred of our overseas military bases -- that would still leave us with hundreds -- and use the savings to help 'harden' America against the inevitable future wars we will see.