State spending on charter schools has emerged as a central element in the debate over whether the constitution should be amended to allow the state to authorize and pay for more charters.

In announcing his opposition to the proposed amendment on Tuesday, Georgia Schools Superintendent John Barge said the state should not create another path for approving charters when it has struggled to pay for the traditional public schools that are already operating.

Amendment opponents are arguing that, under new funding rules, state-approved charter schools will get more state money per pupil than traditional public schools.

That's true, according to an analysis of school funding performed for Gov. Nathan Deal, who backs the amendment, but traditional schools will get local money that state-approved charters won't.

Barge said he's looking to protect the financial interest of taxpayers, who could be asked to pay as much as $430 million over the next five years if the amendment passes and the Georgia Charter Schools Commission is re-created.

Pro-charter amendment forces said that $430 million figure is just a guess because there is no way of knowing how many charter applications would be approved.

"It's a stab in the air in terms of trying to figure out how many schools would be approved," said Bert Brantley, a former spokesman for Gov. Sonny Perdue who is now pushing for passage of the charter schools amendment. "They went out five years to make the number big."

Barge said the $430 million is an estimate, but it's not a figure his staff pulled from thin air. It's based, he said, on new charter funding rules and on how many five-year charters the commission granted when it was operating.

Charter schools are public schools that have been given organizational and curriculum flexibility to meet state and federal education standards. Most of the charters in Georgia were approved by local school boards and receive funding from the same pots of money traditional public schools draw from: the federal government, state money based on an education formula, and local property tax money.

Some charter schools, however, were not approved by the local school board and were approved at the state level, often by the Georgia Charter Schools Commission.

It used to be that such state-approved charter schools would still receive local property tax money, despite the local school board's rejection of their application for a charter. But in 2011, the Georgia State Supreme Court ruled that the Georgia Charter Schools Commission did not have the constitutional authority to approve charter applications. Local boards, not the state, are empowered to oversee K-12 education, the court ruled.

That ruling killed the commission -- and closed the local property tax pot of money to state-approved charter schools.

Earlier this year, pro-charter legislators succeeded in getting the Legislature to change the funding rules to try to bring funding levels for charter schools closer to that of traditional public schools.

According to the analysis by the governor's office, the most common type of state charter school, so-called "brick and mortar" schools that have a physical location, will receive an average of $7,409 per pupil in state funds; brick and mortar traditional schools will receive $5,307 per pupil from the state.

If the amendment is adopted, commission-approved charters will still receive no local tax funds, however. Most charter schools have been approved at the local level and do receive local property tax money, just like traditional public schools.

In the governor's analysis, which did not include federal or private grant funding, local property tax money accounts for 41 percent of the per-pupil average received by traditional public schools and charter schools with local approval.

Barge argued that going through the local school board to receive a charter is the best route. In a 29-point position statement spelling out his opposition to the charter schools amendment, the superintendent said the costs of re-creating the charter school commission and approving more state charter schools is too high.

"Rather than spending millions of dollars on lobbying for a new state agency, amendment advocates should spend that money on developing high quality charter school applicants that our local school districts can easily approve," he said.

CHARTER BASICS

Charter schools are public schools that are independently managed and given organizational and curriculum flexibility while meeting state and federal education standards.

Such schools are approved by local school boards or, if rejected by the local board, by the state Board of Education. The Georgia Charter Schools Commission used to serve as another route to having a charter application approved, but the state Supreme Court ruled in 2011 that the commission lacked constitutional authority.

Charter school supporters fear the state Board of Education's power to authorize schools could also be challenged, potentially limiting charter school growth.

Pro-charter legislators were successful in their push to have a proposed amendment to the constitution placed on the ballot this fall. If it is approved, the commission will be re-established.

Opponents argue the state is not adequately funding traditional public schools and that authorizing and giving state money to more charter schools would hurt traditional public schools.

Backers say the amendment is necessary to guarantee the state's power to authorize and fund charter schools, which they describe as an important choice for parents of children attending failing traditional public schools.