"Without question, the legislature faces substantial challenges in preparing the state budget, particularly during difficult economic circumstances," Judge Michael J. Brown wrote in the ruling, which you can find here. "But our constitution does not permit the legislature to chance the meaning of voter-approved statutes by shifting funds to meet other budgeting priorities."

The decision overturns a Maricopa County Superior Court decision that concluded the Legislature did not have to increase funding to keep pace with inflation.

The inflation funding was included as part of a proposition that created a .6-cent per dollar sales tax to support education. Voters passed Prop 301 in 2000.

Attorney Tim Hogan, who lead the lawsuit against the state, called the ruling a "terrific decision."

"The court upheld the will of the voters, who approved this required inflationary funding," said Hogan, executive director of the Arizona Center for Law in the Public Interest. "Giving some vitality to the Voter Protection Act is important. And this is a significant amount of money, too."

Hogan said the decision to not increase funding to keep up with inflation cost the schools an estimated $87 million this year. But he added that, from his reading of the appeal, the state would not be obligated to provide that funding in this fiscal year; instead, if the decision is upheld by the Arizona Supreme Court, the Legislature will have to provide the inflation-related funding in future years.

Hogan expects Attorney General Tom Horne to appeal the decision.