I was listening to C-SPAN radio this morning, and the governor of Montana was on. He said that governors wake up each morning thinking mainly of three things: education, medication, and incarceration. Overall, depending on how you count, these three things add up to about 75% of state budget expenditures.

Health care is very understated because it encompasses a lot more than Medicaid alone, including health care benefits and pensions of current and former state employees. The note at the bottom bears this out a bit. It should be really about 25%.
Corrections is also quite understated, because it doesn't include law enforcement and the judicial system, both of which of course are involved in the entire process of incarceration. It should be really about 10%.
As the site where this came from points out, these are averages, and the %s can vary widely from state to state. From the site:
"For example, Alaska and West Virginia each spend 11 percent of their budgets on K-12 education, while Michigan, at the other end of the spectrum, spends 31 percent. Similarly, Medicaid makes up 10 percent or less of state budgets in Alabama, Hawaii, and Wyoming but more than 30 percent of the budgets in Maine, Missouri, and Pennsylvania."
