WASHINGTON, Sept 10 (Reuters) - On the campaign trail, Republican presidential candidates vow to roll back new U.S. education standards known as the Common Core.
In the classroom, the multi-state guidelines increasingly look like they're here to stay.
Since they were adopted by 46 states five years ago, the Common Core standards have become a symbol of Big Government overreach for conservatives.
Republican Senator Ted Cruz, a White House contender, has promised to "repeal every word of Common Core." Rivals Bobby Jindal and Chris Christie, both governors who previously backed the standards, now condemn them. Of 17 Republican candidates, only Jeb Bush and John Kasich are Common Core defenders.
Yet despite years of effort, Common Core's critics have largely failed to repeal the standards, which aim to emphasize critical thinking over rote memorization.
In some states, education officials have been reluctant to wipe the slate clean after spending millions of dollars to train teachers and develop new course work. Teachers have also become vocal Common Core backers, lobbying parents and politicians to keep the new system in place. And any Republican president would find it difficult to abolish a system that has mostly been implemented by states.
Two states that have rolled back the standards have replaced them with nearly identical guidelines, while nine states that are reviewing them are likewise expected to leave them largely intact.
"In most places, the political battle has been won by the defenders of the Common Core," said backer Michael Petri, president of the conservative Thomas B. Fordham Institute.
Conservative activists, meanwhile, are frustrated that they haven't had more success.
"I would give up my right pinky if any of these states come up with standards that are substantially different from Common Core," said Erin Tuttle, an Indiana homemaker who worked to repeal the guidelines only to see state officials replace them with a similar set of standards.
At the center of the controversy is a long-standing tension within U.S. education.
Business leaders say U.S. schools must become more consistent and rigorous in order to turn out graduates who can help the country compete in the global economy.
International tests often show that U.S. students lag their peers in other industrialized countries. In one 2012 math test, they ranked 27th among the 34 members of the Organization for Economic Cooperation and Development.
Meanwhile, some parents worry that distant government and corporate interests are hijacking schools, which in the United States historically have been controlled at the local level.
Although Common Core was developed by Republican and Democratic governors and state education officials, President Barack Obama also played a significant role by encouraging states to adopt it through a $4.4 billion grant program in 2009.
Common Core also has been caught up in a backlash against standardized testing, which critics say stifles creativity and eat up too much classroom time. These complaints predate Common Core by more than a decade, but they have been intensified as schools have revamped their tests to reflect the new standards.
Half of all high school students in some districts in Washington state and Long Island, New York boycotted Common Core-linked standardized tests earlier this year.
In the coming school year, nine states will abandon tests that were developed to accompany Common Core in favor of their own assessments. Experts say that will make it more difficult to compare results across state lines.
But even as the tests change, the standards are becoming deeply embedded in the nation's schools as teachers incorporate them into their lesson plans.
"This is the best shift in education I've seen since I started teaching 25 years ago," said Debra Troxell, a high-school geography teacher in Forsyth County, North Carolina.
The Common Core standards spell out what students should know at the end of the school year, but leave implementation to teachers and local officials. For instance, sixth graders are expected to understand statistical concepts, while high schoolers are expected to write essays advancing an argument.
Business groups and other backers say the standards better prepare high school graduates for the workforce. Teachers' unions back the standards as well, though they oppose linking test results to teachers' pay.
The standards have a powerful advocate in Microsoft Corp founder Bill Gates, who has spent more than $200 million to promote them.
But the standards have baffled some parents who struggled to understand their children's homework, building on concerns about too much testing and lack of local control.
South Carolina repealed Common Core in 2014. But officials there have since adopted new standards that are 90 percent similar, according to a state oversight committee. Indiana's new standards also largely mirror Common Core.
Oklahoma has reverted to its pre-Common Core standards while officials develop a replacement. Eight other states are reexamining the standards, but there is little expectation of a major departure in policy.
"It's sort of like putting a cow in a horse costume. It's still a cow," said Emily Mitchell, a kindergarten teacher in Smyrna, Tennessee.
At this point, conservative activists are looking to the presidential race, rather than trying to roll back Common Core at the state level, said Adam Brandon, head of FreedomWorks, a libertarian-leaning grassroots network.
"Are they happy? No," Brandon said. "But the Republican nominee for president, chances are, is going to be very much against Common Core."
That may not mean much, though. Whoever wins the election in 2016 is likely to have less sway over education than Obama because Congress is advancing legislation to prohibit the federal government from influencing state learning standards.
By that point, backers say, Common Core will have already transformed U.S. education.
"We've seen Common Core hold pretty true across the country," said Chris Minnich, executive director of the Council of Chief State School Officers. (Reporting by Andy Sullivan; Editing by Kevin Drawbaugh and Stuart Grudgings)
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