Nearly everyone agrees the fix needs fixing. The No Child Left Behind law that was supposed to improve American education has left schools grumbling at being labeled “failures,” state officials fuming and complaints everywhere about required testing.

But President Barack Obama’s response on Friday — he’s allowing states to opt out — is starting a new round of heated arguments.

There are questions about whether letting states bypass unpopular proficiency standards will help the nation’s schoolchildren. And, even as states clamor to use the new waiver option, some lawmakers say Obama is inserting politics in what had been a bipartisan approach to education.

At the White House, the president said he was acting only because Congress wouldn’t. He decried the state of U.S. education and called the “No Child” law — a signature legacy of President George W. Bush’s presidency — an admirable but flawed effort that ended up hurting students instead of helping them.

Obama’s announcement could fundamentally affect the education of tens of millions of children. It will allow states to scrap a key requirement that all children show they are proficient in reading and math by 2014 — if those states meet conditions such as imposing their own standards to prepare students for college and careers and setting evaluation standards for teachers and principals.

Kids will still have to take yearly tests in math and reading, although the administration says the emphasis will be more on measuring growth over time.

The impact on school kids could vary greatly depending on how states choose to reward or punish individual schools. Under No Child Left Behind, children who attend schools deemed failures after a set period of time are eligible for extra tutoring and school choice. Under the president’s plan, it’s up to states granted waivers to decide if they will use those same remedies.

A majority of states are expected to apply for waivers, which would be given to those that qualify early next year.

State officials have long complained that if they had more flexibility, they could implement positive changes. Now, they will have to step up and prove it.

“This is really going to change things because it really does put responsibility squarely on the states,” said Amy Wilkins, a vice president at Education Trust, a nonprofit that seeks to raise achievement standards in schools.

Officials from Kentucky, Idaho, Wisconsin and Colorado were among those expressing support for the president’s plan Friday.

“I look forward to the federal government narrowing its role in education and allowing Tennessee the flexibility to abide by its own rigorous standards,” Tennessee Gov. Bill Haslam, a Republican, said at the White House event.

But Rep. John Kline, R-Minn., who chairs the House Education Committee, wrote in an editorial Friday published in The Washington Examiner that the plan “could mean less transparency, new federal regulations and greater uncertainty for students, teachers, and state and local officials.”

Sen. Mike Enzi, R-Wyo., the ranking member on the Senate committee that oversees education, said the president’s action “clearly politicizes education policy, which traditionally has been a bipartisan issue that attracts support from both parties.”

The president’s plan is likely to feed the story line by Republicans that Obama is aggressively expanding the presidential footprint, particularly since some people might view it as unconstitutional to go around Congress to get around the law, said Frederick Hess, director of education policy studies at the American Enterprise Institute.

“In pushing this way, the administration makes it likely that education is going to be much more of a partisan divide leading up to the 2012 election,” Hess said.

During Thursday night’s campaign debate in Orlando, Fla., the Republican presidential candidates echoed a common refrain about the federal government’s role in education. Mitt Romney said, “One, education has to be held at the local and state level, not at the federal level.” Said Rick Perry, “The federal government has no business telling the states how to educate our children.”

Despite allowing states to do away with the approaching 2014 deadline, Obama insisted he was not weakening the law but rather helping states set higher standards. He said that the current law was forcing educators to teach to the test, give short shrift to subjects such as history and science and lower standards as a way of avoiding penalties and stigmas.