“Voucher” is a fighting word in education, so it may be understandable that when Mitt Romney speaks about improving the nation’s schools, he never uses that term.

Nonetheless, as president, Romney would seek to overhaul the federal government’s largest programs for kindergarten through 12th grade into a voucherlike system, he said recently. Students would be free to use $25 billion in federal money to attend any school they choose — public, charter, online or private — a system, he said, that would introduce marketplace dynamics into education to spur academic gains.

His plans, presented in a speech at the U.S. Chamber of Commerce, represent a broad overhaul of current policy, one that reverses a quarter-century trend, under Republican and Democratic presidents, of concentrating responsibility for school quality at the federal level.

“I will expand parental choice in an unprecedented way,” Romney said, adding that families’ freedom to vote with their feet “will hold schools responsible for results.”

His proposals are the clearest sign yet that Republicans have executed an about-face from the education policies of George W. Bush, whose signature domestic initiative, the No Child Left Behind law of 2002, required uniform state testing and imposed penalties on schools that failed to progress.

Now Romney is taking his party back to its ideological roots by emphasizing a lesser role for Washington, replacing top-down mandates with a belief in market mechanisms. It is a change driven in part by Tea Party disdain of the federal government. In the Republican presidential nominating fight, candidates competed in calling to shut the Education Department.

Romney, who never went that far, also seems hemmed in politically by the fact that President Barack Obama promotes many solutions that were once Republican talking points — such as charter schools and teacher evaluations tied to test scores.

“There’s not much left for Republicans to be distinctive about,” said Chester E. Finn, Jr., president of the Thomas B. Fordham Institute, an education policy group. “The one line the Obama folks have refused to cross is the voucher line” — that is, allowing students to use taxpayer money to attend any certified school, even a private school.

Specifically, Romney proposed to change federal payments made to schools with large numbers of poor and disabled students into an individual entitlement. Students would take a share of the $25 billion in two federal programs to the school of their choice.

He would also extract the federal government from intervening to turn around the lowest performing schools, which has been a chief focus of the Obama administration. Instead, to drive improvement, Romney would have schools compete for students in a more market-based approach to quality.

“This is the best motive to reform there will ever be — if you give parents the ability to vote with their feet,” said Tom Luna, Idaho’s superintendent of schools, who is an adviser to Romney.

But there is limited evidence in the real world of schools improving much as they compete for students, according to education experts.

One notable skeptic is Margaret Spellings, a former education secretary under Bush, who this year was an informal adviser to Romney. She said she withdrew once the candidate rejected strong federal accountability measures.

“I have long supported and defended and believe in a muscular federal role on school accountability,” Spellings said. “Vouchers and choice as the drivers of accountability — obviously that’s untried and untested.”

Although offering economically disadvantaged children an escape from a failing neighborhood school may be a matter of fairness, Romney’s argument is broader: Choice, he said, will spur competition for students and, like a rising tide, lift all schools.

One recent study of a Florida program offering private school vouchers to low-income families found that test scores at public schools, faced with competition, went up.

But critics say the improvements are small, and that the idea is shaped by ideology more than evidence.

“Romney is on poor empirical ground in making a claim based on competitive effects,” said Christopher Lubienski, an education professor at the University of Illinois.

James Kvaal, policy director of the Obama campaign, accused Romney of seeking to “stop the clock on decades of reform by no longer insisting action be taken when a school has been struggling for years.”

Advocates for vouchers say they will have a larger impact if they become more widespread.

One of Romney’s ideas for increasing students’ choices seems to contradict an anti-Washington emphasis: giving poor students the freedom to choose a public school outside their district.

District boundaries have long been sacrosanct. They prevent urban students, for example, from enrolling in suburban schools that typically have higher-income families and sometimes more lavish budgets.

Calls for open enrollment across districts are usually the province of liberal groups, said Kevin Carey, director of education policy at the New America Foundation, a nonpartisan research group. “For the federal government to require districts to open up their boundaries would be a level of federal intrusion into the affairs of states and local districts far beyond anything” in current law, Carey said.

Romney’s policy seems closely inspired by a pro-voucher report issued in February by the conservative Hoover Institution. Five of eight members of a task force that produced the report are among the 19 education advisers the Romney campaign named last month.

Once thought to be moribund, the voucher movement was revived by gains Republicans made in the 2010 midterm elections. Fourteen states since then have introduced or expanded private school vouchers, according to the Friedman Foundation for Educational Choice.

The money for the vouchers would come from two federal programs that Romney would overhaul, which target students deemed in need of extra support: Title 1, for economically disadvantaged students; and the Individuals with Disabilities Education Act. Currently the money from both programs, the largest K-12 initiatives in the Education Department, is awarded to states and districts based on federal formulas.

Grover J. Whitehurst, a Romney adviser, said that remaking the programs into individual payments that follow the student — he used the metaphor of a student’s backpack — could attract other streams of education dollars.

“If you connected state funding with federal funding, then you’re talking about a backpack with enough money in it to really empower choice,” said Whitehurst, director of education policy at the Brookings Institution. “The idea would be the federal Title 1 funds would allow states that want to move in this direction to do so, and if they did so, all of a sudden it’s a game changer.”

© 2012 The New York Times Company