Washington ? President Bush asked for it. Sen. John Kerry voted for it. Both candidates now find their education agendas driven by the No Child Left Behind law.

The most aggressive shake-up to schools in a generation, the law is the top education issue in a presidential race dominated by war, terrorism, jobs, taxes and credibility. The law orders schools to ensure all children achieve regardless of race, ethnicity or income.

For voters, the line dividing Bush and Kerry is subtle. The nominees diverge on how much to spend on the law and how much to tinker with it as schools try to comply.

The Republican incumbent promotes his spending record. He also says it is time to expand the law by requiring two more years of state math and reading tests in the high school grades.

Kerry says schools need much more money to meet high standards. He promises an extra $10 billion a year by erasing Bush’s tax cuts on people earning more than $200,000. The Massachusetts senator talks of expanding the way student progress is measured in a law built on testing.

Both candidates have ideas all along the education spectrum, from college aid and teacher pay to high school rigor and math and science classes. Some ideas are modest; others would continue an expanding federal role in schools.

Yet all this is largely unnoticed by voters and lightly mentioned by the candidates, even though the next president will take on a backlog of school matters affecting millions of people

“People are still concerned about education, but terrorism and personal security have significantly increased in concern,” said Republican pollster David Winston. “And then you’ve got a rough economy, made worse by 9-11. People are managing a lot more things.”

The result has been a vastly different campaign than the one four years ago. In 2000, Bush was the Texas governor and made education a successful theme of his presidential bid. His focus on schools, traditionally a Democratic issue, helped mold his national image.

Democratic presidential candidate Sen. John Kerry, D-Mass., greets the crowd at an early vote kickoff rally in Pembroke Pines, Fla. Kerry visited Florida and Ohio on Sunday while President Bush took a rare day off the campaign trail.

In office, he won bipartisan support in 2001 for No Child Left Behind, which calls for all students to reach state standards in reading and math by 2014. Parents get more school choices, but many schools face penalties if even a single subgroup of students falls short.

The law has not been a clear boon for Bush. States have balked at what they call federal intrusion.

“He got that law passed and has focused people on the problem of the achievement gap, and that is a big accomplishment,” said Diane Stark Rentner, deputy director of the independent Center on Education Policy. But, she said, Bush did not follow through on his spending promises — a point of endless dispute.

Under Bush, spending on the law’s programs and on help for disabled children has grown from $24.7 billion to $35.5 billion, a 43 percent increase. Counting his current budget request, the increase during his term would be 49 percent, a number he cites while campaigning. Those figures would not be as high if Congress had not added billions to Bush’s requests.

But Democrats say Bush has shortchanged the law by up to $28 billion. As a result, they say, everything from teaching to testing has suffered.