A Senate vote today is expected to seal the approval of the biggest federal education reform in more than 35 years.
It will mark one of the major achievements of a legislative session that, on other big issues, remains mired in gridlock. Both parties made important compromises to strike a deal.
But some of those very compromises helped set the stage for a bigger challenge: implementing the bill's bedrock goal of accountability in the classroom.
Student testing will be mandatory, but under the law the tests can vary from state to state, and parents may even have a hard time comparing schools among neighboring districts. Moreover, new federal money for the states is already being counterbalanced by cutbacks at the state level.
Indeed, with an election year looming and recession sapping state tax revenues, it may take as powerful an exertion of political will to implement this reform as it did to get it passed.
"This education plan is only as good as its enforcement and implementation effort," says Amy Wilkins, senior partner in the Washington-based Education Trust, a public-interest group that lobbies for poor children in education. "That will be the test of Bush's mettle: when he has to stare down state governors and say, 'Yes, you will,' when they say, 'No, we won't.' "
In the end, the No. 1 legislative priority of the Bush White House came down to one big compromise merging conservative and liberal goals: Schools will measure student achievement and be held accountable for the results - but failing schools will also get extra resources to improve.
For the first time, the federal government is requiring states to test students in Grades 3 to 8 annually in reading and mathematics - and imposing penalties for schools that fail to make progress toward proficiency for all students in these areas.
Reformers hope that publishing a clear record of student achievement every year will empower parents to demand more of their schools.
It would begin the last leg of an accountability effort that started 15 years ago.
While some states, such as Massachusetts, already conduct testing, parents in prosperous suburbs often believe the tests stifle innovation by encouraging educators to "teach to the test." But results in some Southern states and inner-city schools have shown dramatic progress.
Reaching a deal to take testing nationwide was a stretch for legislators on both sides of the aisle. As Democrats pushed for more money for poor schools, some Republicans wanted to abolish the Education Department.
"I could see that we weren't going to be able to eliminate the federal role. [But] I thought we ought to have some results for what we invest," says Rep. John Boehner (R) of Ohio, once a leading proponent of getting Washington out of schools.
He helped broker a deal in the House, leading toward the most significant increase in education spending in a generation.
Key Democrats, meanwhile, warmed to President Bush's interest making reading skills for poor children an urgent priority.
To achieve that goal, the law will demand that schools report test scores by race, ethnicity, and income - measures that make it hard to hide poor results for these groups.
"I warned him this would be quite a fight with governors, and he assured me he could deal with them," says Rep. George Miller (D) of California.
On the Senate side, Edward Kennedy (D) of Massachusetts, the dominant voice in federal education policy since the 1960s, cracked down on liberals in his own party who wanted to fight for an extra $74 billion in education spending over the next 10 years.
But the president's original plan lost much of its edge on the way to becoming a law. Governor Bush's Texas measured all school districts by the same test.
But the federal law will allow school districts to choose their own tests, thus making it harder to compare student performance across districts.
Also, parents with children in failing schools will not be allowed to use federal funds to send their kids to private schools - a feature of the original Bush plan dear to conservatives. (The bill does give parents of children in failing schools new resources, such as the ability to use federal funds to pay for tutors or after-school programs.)
Still, the requirement to report annual results will be a big incentive for states to pay attention to their most vulnerable students, supporters say.
The question is whether they have the resources to do anything about problems, once they are identified.
Already, school administrators warn that states are being forced to cut back funding for schools as a result of a 10-month recession. Many state legislators are cutting education in anticipation of new federal dollars that will offset them.
"The assumption has been that states would maintain their efforts and new federal spending would be on top of what is already being done. That is clearly not going to be the case," says Bruce Hunter, director of government relations for the American Association of School Administrators.
"Unless there is a change in the economy and a big influx of money to the states, which is unlikely, it will slow down implementation [of the new education law]," he adds.
Nor are resources the only obstacle to carrying out new reforms. Many critics assailed the Clinton administration for failing to muster the political will to implement the last round of education reforms in 1994, which required states to come up with their own standards and tests and to evaluate whether students were meeting them.
"It's not in the best political interests of the president to come down hard on governors of the same party - or even of the other party," says Marshall Smith, deputy secretary of Education under President Clinton. "That's not going to be any different for the Bush administration."
Governors have closely followed the negotiations on this bill, and weighed in on key points. GOP governors helped force revisions of an early accountability formula that had been adopted by both the House and Senate.
If that formula had become law, it would have identified most schools as failing to meet the new standards, even in reform-minded states like North Carolina and Texas. The revised formula sets a lower standard for states to meet.
Congressional leaders say they have a commitment from the White House that the administration will resist efforts to further dilute the plan.
"I don't think you will have to worry about a whole lot of waivers coming out of this Department of Education," says Mr. Boehner of the House GOP.