The Washington Post:

As public schools across the country transition to the new Common Core standards, which bring wholesale change to the way math and reading are taught in 45 states and the District, criticism of the approach is emerging from groups as divergent as the tea party and the teachers union.
The standards, written by a group of states and embraced by the Obama administration, set common goals for reading, writing and math skills that students should develop from kindergarten through high school graduation. Although classroom curriculum is left to the states, the standards emphasize critical thinking and problem solving and encourage thinking deeply about fewer topics.
But as the common core shifts from theory to reality, critics are emerging. State lawmakers are concerned about the cost, which the Fordham Institute estimated could run as high as $12 billion nationally. Progressives fret over new exams, saying that the proliferation of standardized tests is damaging public education. Teachers worry that they haven’t had enough training and lack the resources to competently teach to the new standards. And conservatives say the new standards mean a loss of local control over education and amount to a national curriculum. They’ve begun calling it “Obamacore.”
On Tuesday, the head of the American Federation of Teachers and a strong supporter of the Common Core standards will warn that the new approach is being poorly implemented and requires a “mid-course correction” or the effort will fall apart.
“The Common Core is in trouble,” said Randi Weingarten, the union president who is slated to speak Tuesday in New York about the issue. “There is a serious backlash in lots of different ways, on the right and on the left.”