When it comes to school reform, President Bush backs high standards and high-stakes tests, which form the core of the education plans currently before Congress. By contrast, Rebell believes in “throwing money” at schools, an objective that he’s discovered can sometimes be accomplished by suing states to force them to spend more money on urban school districts, where per-pupil spending tends to lag far behind that of suburban schools. He’s just won a victory in New York, and has set up a network of lawyers, professors, and politicians to press this case nationwide.

So it may seem odd that Rebell is excited about Bush’s education plan. It’s not that he favors Bush’s policies so much as what they’ll produce: detailed test scores that measure student learning. Or, in his eyes, a potential bonanza for lawsuits. He’s probably right. Difficult as it may be for supporters of accountability to accept, the tests are likely to provide lawyers like Rebell the motherlode of evidence they need to sue states (and possibly the federal government itself) to release the flood of new money for urban schools for which liberals have long thirsted.

Back in the late 1960s, when Rebell was still studying at Yale Law School, liberals were becoming frustrated with the slow pace of change following the 1954 Brown v. Board of Education decision. They began to argue that in order to guarantee Brown’s endorsement of equal access, the federal government needed to ensure equitable education funding for all children. They tested this strategy in a lawsuit, which charged that underfunding of the school system in San Antonio, Texas, violated the 14th Amendment to the Constitution, which guarantees equal protection. But the argument failed to persuade the Supreme Court, which ruled in San Antonio Independent School District v. Rodriguez, in 1973, that education was not a “fundamental right” under the Constitution, stressing that Rodriguez’s lawyers had failed to provide a mechanism to asses relative differences in the quality of education and their connection to spending.

Following Rodriguez, liberal lawyers turned their sights on the states, arguing that unequal school financing violated the equal-protection clauses in state constitutions. This strategy worked for a while in such states as California, New Jersey, Arkansas, and Connecticut. But the courts gave the states little guidance to fix these complicated problems.

In many cases, what resulted in the classroom was the opposite of what advocates had intended. The California Supreme Court, for example, ruled that the spending gap between rich and poor districts could not exceed $100 per student. So taxpayers simply stopped spending money on education. California has since dropped from fifth to 46th in the country for state spending per student—edging out Mississippi, which ranks 47th.

By the mid 1980s, it had become clear that these cases weren’t producing better schools for poor children. State court judges gradually accepted the rationale of the Rodriguez decision. By 1988, school-funding suits failed in seven states, succeeding in only two.

The following year, President George H.W. Bush convened the first National Education Summit with governors and business leaders, which agreed that schools needed more guidance in how to improve their curricula, and began working on a set of national goals. They concluded that states needed to develop a set of statewide “standards” that set out what children should be expected to know in each grade, thus initiating the standards movement.

The concept of standards in education turned out to be a breakthrough for the lawyers. The problem that courts had with the old “equity” argument was the plaintiffs’ inability to prove that low-income students were truly getting a poor-quality education. But if states set standards for what students should know, and used tests to measure the progress toward meeting them, the lawyers would finally have the evidence they had lacked.

With that in mind, judges in Kentucky that same year ruled in favor of the plaintiffs in a school-financing suit and inaugurated an entirely new rationale of “adequacy.” Instead of arguing about inequitable financing, they ruled that Kentucky had violated the right laid out in its state constitution of all children to be provided a basic education. Equity looked at the amount of money going in; adequacy examined the quality of education coming out. The Kentucky Supreme Court found the entire state school system “underfunded and inadequate.” By measuring adequacy through tangible factors like student-teacher ratios, curriculum, and teacher pay, the court was able to declare the system itself unconstitutional and order the state to adjust spending so that it was “sufficient to provide each child in Kentucky an adequate education.”

As more and more states joined the standards movement and developed statewide tests, they made it easier for lawyers like Rebell to prove their case. Test-score gaps which correlated with funding gaps proved highly persuasive to state courts. “You also have a focus on where the gaps are,” explains Rebell, a lecturer at Columbia University Law School. “The evidence is clearer who is failing by how much they are failing.” Since 1989, the adequacy argument has won mandates to equalize funding in 18 of the 28 such cases.

In 1993, prodded by a parent who chaired his local school board in New York City, Rebell formed the Campaign for Fiscal Equity (an umbrella outfit for parents and school board groups in his class-action suit) and sued New York state, in an action which reveals how important test scores are in building a case.

The suit hinged on the yawning divide between the test scores in New York City and in the wealthy suburbs nearby. In the city, only 44 percent of fourth-graders met state reading standards last year. In nearby Chappaqua, that number leapt to 96 percent, a gap which correlates with funding: New York City spends about $10,000 per pupil, the state covering 43 percent of that cost. In Chappaqua, by contrast, 93 percent of the nearly $16,000 spent per student comes from local property taxes. City schools also receive around $2,000 less in state funds per student than similarly strapped school districts in cities like Buffalo or Yonkers. (Still, schools in New York spend much more per student than the national average of around $6,800.)

These well-documented spending and test-score gaps persuaded the court. In January, Judge Leland DeGrasse ruled that New York City students “are not receiving a minimally adequate education.” He indicted the quality of the city’s teaching force, surging class sizes, minimal use of instructional technology, and dilapidated school buildings as sources of the city’s sagging test scores and 30-percent dropout rate and concluded that “increased educational resources, if properly deployed, can have a significant lasting effect on student performance.”

If Rebell prevails on appeal—the national trend suggests he likely will—New York will be faced with an additional annual outlay of about $3 billion on top of its $13 billion annual education budget. That’s a bigger boost for just New York City than the entire $2.4 billion increase which Bush originally had planned for the entire federal education budget. (Democrats eventually pushed the total to $7 billion.)

And New York is just the latest example of this trend. It echoes the recent experiences of states like New Jersey, Ohio, and Wyoming, where judges have been equally sympathetic to claims of educational inadequacy and have required the states to spend more money to fix it. Those states currently rank among the biggest spenders (per student) in the country.

If Bush’s education bill, or some version of it, passes Congress, it will mean big business for Rebell and his allies. Requiring states to test students in grades 3 through 8 every year in reading and math, as Bush’s plan does, will produce detailed measurements of how many students are meeting states’ standards. That sounds like common sense, but most states don’t do this. And the veracity of these state tests will be checked against a nationally administered test. If done properly, states will have much higher quality data than they do now—and tons of it.

While only 15 states currently test that much, soon every state will, which means every state will be exposed to lawsuits arguing that the reason students in poor school districts don’t measure up is that the states are not spending enough on those students.

Thanks to Bush’s plan, Washington itself could be liable—lawyers may soon have high-quality, nationally comparable state test scores which will allow them to prove what the plaintiffs in Rodriguez 30 years ago could not. If they’re able to link this data to particular kinds of reforms—say, smaller class sizes—then lawyers could provide the courts with a remedy to increase test scores in poor districts. With such comprehensive evidence, it may be possible to argue to the Supreme Court that national government’s failure to pay for such reforms violates the 14th Amendment—a possibility of which education activists are fully aware. “We will never have a better chance,” says Bruce Hunter, the director of public policy at the American Association of School Administrators. “In five or 10 years, the people who gave us this [annual testing] are going to rue the day that they did.”

All of these cases beg the question of whether more money actually will improve schools. The short answer is: It depends. It hasn’t in New Jersey, which now spends more per student than any other state. According to last year’s statewide tests, more than half of New Jersey’s fourth-graders can’t read proficiently, even though the state spends more per pupil than any other. On the other hand, money appears to have helped in Kentucky, where the court ruling required an overhaul of the school system that focused on setting goals and measuring student’s progress. It pumped more money into poor schools, established tough standards, and boosted teacher pay. The performance in state and national tests of students in every racial and economic category has improved over the last decade, even though overall performance remains low. And 10 years after Kentucky’s reforms, the funding gap between rich and poor districts has only narrowed from $1,199 per student to $757 per student.

Using courts to obtain that money has a number of downsides. Like all legal remedies, it’s inefficient. Lawsuits can take years to play out because they are subject to endless appeals and finagling by politicians. After 28 years, the New Jersey case is still being fought; Ohio has spent a decade in court; and experts expect Rebell’s New York case to drag on for at least another five to 10 years. Already, the legal fees are approaching $25 million.

In addition, court-ordered remedies short-circuit the political process, which angers voters. Indeed, it cost at least one politician his job. In 1993, then-New Jersey Gov. Jim Florio lost his re-election bid after he raised taxes to pay for $1 billion that the courts had required.

Some, especially in Bush’s camp, also charge that lawsuits could stall the accountability movement. Erik Hanushek, a senior fellow at Stanford University’s Hoover Institute who advised Bush’s presidential campaign, argues that testing-inspired litigation could stall any other school reforms until the suits run their course because the state legislatures are so preoccupied with responding to the court’s demands that little else can be done on education. “These lawsuits, at least when they’re successful, tend to, in fact, impede significant reform in the schools,” he said. “I think it would be very bad for U.S. education.”

But there are ways out. The easiest way to avoid lengthy legal battles is to close the test-score gap, so that lawyers like Rebell don’t have a case. The catch is that doing so will probably cost many states billions of dollars, just as they’re struggling to ward off deficits. Of course, states which get dragged into court for allowing that test-score gap to persist are likely to be forced to pony up not just for reforms, but for millions in legal fees as well.

If he wants to preempt the lawyers, Bush might consider a bigger role for Washington. Given that the federal government’s primary responsibility in education is to make sure—as Bush would say—that no child is left behind, he could offer some version of a matching grant to give states an incentive to equalize per-pupil funding. That arrangement could not only stave off “big trial lawyers” but also give the president a chance to ensure that the money boosts student achievement instead of fattening bureaucracies—another of his favorite targets.

Siobhan Gorman covers education for National Journal.