It's still punishment. There is a lot wrong with our prison system, much of which is a result of overcrowding. We can address those problems as well. But we cannot use the government to maim inmates anymore. That part is over.
Like most other systems governed by the hand of government bureaucracy in the United States, the major problem with our prison system has always primarily lain in the giant mess of compromises and ineffective half-measures that form the intrinsic core of the beast's nature. It has been effectively built from the ground up as a dumping ground for "P.C." committee consensus and the lobbying of special interests.
Simply put, life long imprisonment is the coward's way out. It temporarily pushes a certain problem aside by putting it "out of sight and out of mind." This would be fine... if it weren't for how expensive keeping prisoners detained indefinitely happens to be, just how out unreasonably large our nation's prison population has grown to become in recent years, or the way in which violent crime seems to have actually only gotten worse in spite of this approach to justice.
Again, like most everything else in the modern United States, we are paying far too much for a system which only provides subpar outcomes.
This is never going to change if we don't toss the kid gloves aside at some point and start opting for tougher measures to deal with dangerous repeat offenders. Quite frankly, most of these people deserve no mercy anyway.
I'd probably do it myself if I had the courage and the presence of mind to realize the harm I might cause. However, if I were to happen to possess niether, why would it be wrong for the state to step in and force me to take certain proactive steps in order to curtail my behaviors and ensure the safety of the general public?
We already do this for the mentally ill.
Granted, there would be potential for abuse in such a system. This is why I stated earlier that impariality would have to be guaranteed before I would support such measures.
However, if such impartiality could be ensured, I would see no problem with the idea of mandatory chemical castration for dangerous offenders on a theoretical or moral level.