The United States has, according to Wikipedia, about 750 of every 100,000 inhabitants in jail. That is not merely more than other industrialized countries, but many times more. The UK has a fifth of that at 150 per 100,000, and other countries have much less still - around 100 or less for Canada and many European countries, and Japan apparently has 62 per 100,000.

Now I'll buy that the US may have more crime for all kinds of reasons and that a somewhat higher rate would be natural. But five times as much as the UK, and seven times as much as Canada? At some point you have to start asking what on earth you're doing there - particularly since it doesn't exactly seem like that prison population rate has reduced crime to levels below those in those other countries. The War on Drugs is a large part of the reason, I understand, as many of those 2+ million are in jail for drug-related crimes that wouldn't carry a jail sentence elsewhere. So really, allow me to say that you need less jails if you're going to save money, not even more. And of course such insane amounts of prisoners don't merely require very high expenditures on jails, but there's also the legal costs and the law enforcement that has to arrest them all and get them put in jail. Maybe if you were aiming for a somewhat more natural incarceration rate, you'd find that suddenly the police and legal system didn't need budget increases after all, and could even take a few cuts.