Under the law that Nevada Gov. Brian Sandoval signed Tuesday, low-income families or students with disabilities can receive the same amount the state spends per public school student, or an average of about $5,700, while middle- and upper-income families will receive slightly less, about $5,100 a year. (Kevin Clifford/2011 file photo/AP)

Starting next school year, any parent in Nevada can pull a child from the state’s public schools and take tax dollars with them, giving families the option to use public money to pay for private or parochial school or even for home schooling.

The new law, which the state’s Republican-controlled legislature passed with help from the education foundation created by former Florida governor Jeb Bush (R), is a breakthrough for conservatives, who call it the ultimate in school choice. And they are working to spread it nationwide: Lawmakers in Georgia, Iowa and Rhode Island considered similar legislation this year.

Democrats, teachers unions, public school superintendents and administrators are alarmed, saying that the Nevada law to provide private school vouchers is the first step toward dismantling the nation’s public schools.

Although other states increasingly have allowed tax dollars to be used for private school tuition, most limit the programs to students with disabilities or from low-income families. A few states, such as Indiana, have expanded the option to the middle class.

Nevada’s law is singular because all of the state’s 450,000 K-12 public school children — regardless of income — are eligible to take the money to whatever school they choose.

“It’s just a huge victory for the children of Nevada and all of us who have been working on this for so many years,” said Robert Enlow, chief executive of the Friedman Foundation for Educational Choice, an advocacy group dedicated to the principles of free marketeer Milton Friedman. “What this will do is continue to spread ripples across the country. . . . This bill shows that you can actually politically get it done.”

Supporters of the Nevada plan said lawmakers were obligated to give students alternatives to public schools in the state, which regularly scrapes bottom when compared with other states on academic achievement.

“Nothing works better than competition,” said state Sen. Scott Hammond, the chief sponsor of the legislation. The Las Vegas Republican said he was inspired when he attended a Friedman Foundation seminar during a vacation to Utah last year.

“I think a healthy public school system has choice, and we’re going to see all kinds of schools pop up to serve the individual needs of students,” said Hammond, a longtime public school teacher who will soon become an administrator at a charter school. “I don’t think we’re going to see an exodus from the schools. I think it will be more of a slow, measured response, at least in the beginning.”

In January, Republicans took control of the Nevada legislature and the governor’s mansion for the first time since 1929, generating the political momentum to enact the country’s most expansive voucher plan.

School choice is primed to become a top education issue in the 2016 presidential campaign, as several would-be or declared GOP candidates, including Bush, Wisconsin Gov. Scott Walker and Sen. Marco Rubio (Fla.), seek to spread school choice and vouchers. Democratic front-runner Hillary Rodham Clinton has long been opposed, saying vouchers siphon away scarce dollars from public schools.

“I am terrified that there are more and more state legislators and state governors who have bought into this very dangerous idea that school is a commodity,” said Lily Eskelsen García, president of the National Education Association, which represents 3 million educators.

Vouchers will exacerbate the gap between rich and poor by giving a public subsidy to affluent families that choose elite private schools, which are unlikely to admit students who struggle academically or cannot afford tuition even with a voucher, Eskelsen García said.

“It’s not profitable for very good private schools to allow in children who are disabled, kids who don’t speak English, kids whose parents are struggling to put food on the table,” she said.

Bob Farrace, a spokesman for the National Association of Secondary School Principals, said the Nevada law is a betrayal of the American commitment to public education.

“Funneling public funds to private schools means fewer teachers, fewer counselors, fewer supplemental services and, in general, fewer opportunities for the vast majority of kids who remain in public schools,” he said. “It really violates the public trust when policymakers place individual benefit before public good.”

The measure passed on a party-line vote in both houses of the Nevada legislature. Assemblyman Elliot T. Anderson, a Las Vegas Democrat, said the new program could face a legal challenge because the state constitution prevents “public funds of any kind or character whatever” spent for sectarian purposes.

Friedman, the late University of Chicago economist, presented the idea of school vouchers in 1955 as the ultimate expression of free choice for families. The idea was long thought to be moribund but came roaring back to life in 2010 in states where Republicans took legislative control.

In many ways, vouchers are where the public-charter-school movement was about 20 years ago, a novel idea that is gaining traction, said Patricia Levesque, chief executive of the Foundation for Excellence in Education, which Bush founded in 2008. He resigned from the foundation late last year in anticipation of a presidential bid.

“This is the wave of the future,” said Levesque, whose foundation helped Nevada legislators draft the measure while its nonprofit sister organization, Excel National, lobbied to get it passed. “In all aspects of our life, we look for ways to customize and give individuals more control over their path and destiny. . . . This is a fundamental shift in how we make decisions about education.”

Since 2006, 27 states have opted for one of three methods that transfer public tax dollars to private schools: Vouchers for students from low- and middle-income families or disabled students; tax credits, up to 100 percent of tuition, for donations to private school scholarships; and education savings accounts, which allow qualifying families to use public funds to pay for private school tuition, tutoring, online education and other services.

Under the law that Nevada Gov. Brian Sandoval signed Tuesday, children must be enrolled in a public school for at least 100 days before they can receive a voucher. Low-income families or students with disabilities can receive the same amount the state spends per public school student, or an average of about $5,700, while middle- and upper-income families will receive slightly less, about $5,100 a year.

Nevada has been among the 10 lowest-spending states when it comes to funding public education. According to the U.S. Census, Nevada spent $8,339 per student in 2013, a combination of local, state and federal money. The national average that year was $10,700.

The money is to be set aside in an educational savings account administered by the state treasurer, and parents can withdraw the funds to pay for tuition, fees and textbooks at a private school, or for tutoring, tuition and fees for online learning programs or at a college or university in Nevada that offers dual credit. Home-schoolers can use the money to buy curriculum materials or supplies. Parents can carry over unspent funds from one year to the next.

One Las Vegas parent, identified by the Friedman Foundation as a supporter of the law, said she thinks it will give her daughters access to opportunities.

Aurora Espinoza, a single mother who works as a solar-panel sales representative, said her children’s current public schools — which are among the nation’s fastest-growing — are so crowded that it’s hard for them to learn. She plans to enroll her daughters in private school next year, but she isn’t sure where, nor whether tax dollars will cover the tuition. “I just want the best for them,” she said.

Correction: An earlier version of this article incorrectly reported the year that Milton Friedman introduced the concept of school vouchers. The year was 1955, not 1962.