PHOENIX — Republican lawmakers asked the state Court of Appeals this afternoon to give them a chance to prove that hundreds of millions of dollars being used to support an expanded Medicaid program were illegally enacted.

Attorney Christina Sandefur told the judges the Arizona Constitution is clear: Any measure that raises taxes or increases revenues can be enacted only with approval of two-thirds of both the state House and Senate. But the levy on hospitals which financing the program — Jan Brewer calls an assessment and not a tax — did not get that margin.

And that, Sandefur said, makes it not only illegal but also deprives her lawmakers, who make up more than a third of both chambers, of their constitutional right to block the fee.

Sandefur is making her case to the appellate court because Maricopa County Superior Court Judge Katherine Cooper ruled last year the dissident lawmakers had no right to sue because they had not been injured. Cooper said only those affected by the tax, meaning the hospitals, have standing to challenge it.

But Sandefur said that ignores one key fact: the hospitals have no interest in suing.

"They financially benefit from it," she told the judges. That's because the plan crafted by the governor means more of their patients will have Medicaid coverage and be able to pay their bills. And officials from the Arizona Health Care Cost Containment System, the state's Medicaid program, structured the levy so that no hospital chain would pay more than it gains, even to the point of granting total exemptions to some hospitals.

Hanging in the balance is more than the question of whether the tax on hospitals — an estimated $256 million this coming budget year — can be collected and, by extension, whether there is money for Brewer's Medicaid expansion.

There's also the question of whether a simple majority of lawmakers are free to simply decide that requirement for a two-thirds vote does not apply, free from being challenged by the minority of lawmakers who otherwise would have been able to block the levy. And that clearly concerned Judge Peter Swann.

"That would sort of render the entire constitutional amendment toothless," he said.

"If a simple majority could decide that no supermajority is required, when would a supermajority ever be required?"