The country’s largest teachers union is no longer a cheerleader for Common Core national education standards.

In a letter to the National Education Association’s 3 million members, President Dennis Van Roekel issued a sharp critique of Common Core. It marks the first time NEA has voiced concerns about the standards, a key initiative of the Obama Administration.

I am sure it won’t come as a surprise to hear that in far too many states, implementation has been completely botched. Seven of ten teachers believe that implementation of the standards is going poorly in their schools. Worse yet, teachers report that there has been little to no attempt to allow educators to share what’s needed to get [Common Core State Standards] implementation right.  In fact, two thirds of all teachers report that they have not even been asked how to implement these new standards in their classrooms.

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The NEA once enthusiastically supported Common Core, making Van Roekel’s criticism noteworthy. POLITICO said it meant a “rocky road ahead for the Common Core standards” and would “give opponents of Common Core a boost.”

In his letter, Van Roekel stops short of completely abandoning Common Core, calling instead for a “course correction” to fix implementation.

“NEA members have a right to feel frustrated, upset, and angry about the poor commitment to implementing the standards correctly,” Van Roekel writes.

The National Education Association’s concerns come nearly a year after the American Federation of Teachers raised problems with implementation of the standards. AFT President Randi Weingarten said, “they simply don’t get it in Washington.” She also called the implementation of Common Core worse than

>>> Read More: Common Core Implementation Will Be Worse Than Obamacare

Just last month, New York State United Teachers, part of AFT, voted to pull its support for Common Core. The union consists of 600,000 members in New York.

“Teachers unions shouldn’t be surprised the implementation was botched,” said Lindsey Burke, the Will Skillman Fellow in Education at The Heritage Foundation. “This is what happens with one-size-fits-all bureaucratic initiatives.”

Currently, 45 states and the District of Columbia have adopted Common Core standards, although the intense debate in some states, notably Indiana, could result in changes.