WASHINGTON -- The Supreme Court seemed to divide into liberal and conservatives camps Monday during arguments in a case that could limit the power of federal courts to tell states to spend more money to educate students who aren't proficient in English.

Some of the court's more liberal justices - David Souter and Stephen Breyer - repeatedly challenged assertions by attorney Kenneth Starr that court oversight of Arizona's English learners program was no longer needed because the Nogales Unified School District, located near the state's border with Mexico, had made progress educating students learning to speak English.

Souter pelted Starr, who as special counsel investigated President Bill Clinton in the Monica Lewinsky scandal, with a series of statistics showing a vast gap in academic test scores between Nogales students learning to speak English and native English-speaking students in Nogales and elsewhere in the state.

"I'm sure progress has been made," Souter said, "but it doesn't seem to me that ... you could say the objectives are achieved."

Starr is representing Arizona state legislators and the state superintendent of public instruction, who want to be freed from a lower court order that the state come up with a new program to teach English learners and provide enough money for that program that it can reasonably be expected to achieve its goal. The state could be forced to spend potentially hundreds of millions of dollars to comply.

Starr said the amount of money being spent shouldn't be the issue, but rather that the "sea change" that has taken place in state's efforts to address the problem in the nine years since voters passed a ballot measure requiring intense English immersion for students learning the language. He called the court's continued oversight an intrusion into state government.

A key issue in the case, now called Horne v Flores, is the power of federal courts to take over functions of state or local governments when trying to remedy civil rights violations.

Parents of students attending Nogales schools sued the state in 1992, contending programs for English-language learners were deficient and received inadequate funding from the state.

In 2000, a federal judge found that the state had violated the Equal Educational Opportunities Act's requirements for appropriate instruction for English-language learners. A year later he expanded his ruling statewide and placed the state's programs for non-English speaking students under court oversight.

Since then, the two sides have fought over what constitutes compliance with the order. Arizona has more than doubled the amount that schools receive per non-English speaking student and taken several other steps prescribed by the No Child Left Behind Act, a broader education accountability law passed by Congress in 2002.

Breyer said the state's increased spending still only amounts to $300 to $400 extra per pupil when estimates suggest it cost from $1,570 to $3,300 extra per student to get the job done.

Justice Ruth Ginsburg said the district court was careful not to tell the state what methods of instruction it should use or how much it should spend, only that it come up with a plan to address the problems of English learners and sufficient funding that could be reasonably expected to meet the plan's goals.

But Justice Antonin Scalia, part of the court's conservative wing, said he finds "it bizarre that we are sitting here talking about what the whole state has to do on the basis of one (school) district, which concededly is the one that has the most non-native English speakers."

The case has attracted a flurry of legal briefs from school boards, teachers and civil rights groups in support of the Nogales parents and students. An array of conservative legal foundations have filed briefs in support of the legislators and the superintendent of schools.

The lead plaintiff in the case was Miriam Flores, a Nogales mother. She said her daughter had two years of instruction in her native Spanish, then was put into a class with a teacher who did not speak Spanish, the language the daughter - also named Miriam Flores - spoke at home. She began to fall behind and there were complaints she was talking in class. It turned out she was asking other students to tell her what the teacher was telling the class.