AUSTIN — While lawmakers continue their struggle to fix the state's public school funding system, lawyers for Texas will try to convince Supreme Court justices today that everything is basically OK.

More than 300 Texas school districts are joined in the legal battle for more state funding. Some also contend that Texas has an unconstitutional statewide property tax because so many school districts have reached the maximum school property tax rate for operation and maintenance expenses.

State District Judge John Dietz declared the Texas school system unconstitutional last year because lawmakers were not appropriating enough money to give children an adequate education. He also ruled that the school tax rate had become, in effect, a statewide property tax.

The state's appeal creates a showdown before the Texas Supreme Court, which could take several months to rule.

Texas Attorney General Greg Abbott and his deputies will argue that only legislators — not courts — can determine adequate funding levels for public education.

"The structure and history of the Texas Constitution demonstrates that the authority to design and fund the school system has expressly been assigned to the Legislature," they said in a written brief for the court.

Questions of adequate funding levels and whether the state's education system is efficient are political issues — not ones that can be litigated, Abbott argued.

Lawyers for the school districts counter that they simply need the courts to order lawmakers to do their job.

"We are not asking the court to invade the province of the Legislature or trying to do the Legislature's job," said David Thompson, one of the lawyers representing property wealthy school districts.

The Legislature has done a good job in setting higher academic standards and in supporting new, tougher tests to measure student and school performance, he said.

"And we have not asked the courts to second-guess those policy choices," Thompson said.

But lawmakers fail to meet a constitutional obligation to provide "a general diffusion of knowledge" if they "pass great requirements and never pay for them," Thompson said.

The attorney general and his deputies argue that Texas' accountability measures, standardized testing and required curriculum make it a national leader in education reform.

They want the Supreme Court to apply a "rational basis" to allow the justices to draw a clear line between the proper roles of the courts and the Legislature.

While lawyers for the state contend the current funding system is working fine, Gov. Rick Perry, Lt. Gov. David Dewhurst and other state leaders have criticized it and Perry has called two special legislative sessions to change the way Texas finances public education.

David Hinojosa, lawyer for the Mexican American Legal Defense and Educational Fund, said the state Supreme Court must intervene during a dispute over the constitution.

MALDEF represents Edgewood and the school districts in the landmark 1989 legal fight for equitable school funding.

"When the Legislature fails in their efforts, of course, that's when you have judicial intervention," Hinojosa said.