Corrections Budgets "Unsustainable?"

We constantly hear that our corrections budgets are straining finances and that we spend more on prisons than on schools.  The following chart from the Center on Budget and Policy Priorities clearly indicates that this is not the case.  What we spend on corrections is peanuts compared to other budget line items, especially education and healthcare.  If our country ever goes broke, it won't be because of too much spending on prisons.

Can we lay this myth to rest?  Unfortunately too many people have gotten a lot of mileage promoting it.