A Gallup poll found that while 76 percent of teachers favored nationwide academic standards for reading, writing and math, only 27 percent supported using tests to gauge students’ performance, and 9 percent favored making test scores a basis for evaluating teachers. Such antagonism is well founded — researchers have shown that measurements of the “value” teachers add, as determined by comparing test scores at the beginning and end of the year, are unreliable and biased against those who teach both low- and high-achieving students.

The Obama administration has only itself to blame. Most Democrats expected that equity would be the top education priority, with more money going to the poorest states, better teacher recruitment, more useful training and closer attention to the needs of the surging population of immigrant kids. Instead, the administration has emphasized high-stakes “accountability” and market-driven reforms. The Education Department has invested more than $370 million to develop the new standards and exams in math, reading and writing.

Questioning those priorities can bring reprisals. During the search earlier this year for a New York City schools chancellor, Education Secretary Arne Duncan lobbied against Joshua P. Starr, the superintendent of schools in Montgomery County, Md., in part because he had proposed a three-year hiatus on high-stakes standardized testing.

Last year, Mr. Duncan said that opposition to the Common Core standards had come from “white suburban moms who realize — all of a sudden — their child isn’t as brilliant as they thought they were, and their school isn’t quite as good as they thought they were.”

He has only recently changed his cavalier tune, acknowledging, “Too much testing can rob school buildings of joy and cause unnecessary stress.”

It’s no simple task to figure out what schools ought to teach and how best to teach it — how to link talented teachers with engaged students and a challenging curriculum. Turning around the great gray battleship of American public education is even harder. It requires creating new course materials, devising and field-testing new exams and, because these tests are designed to be taken online, closing the digital divide. It means retraining teachers, reorienting classrooms and explaining to anxious parents why these changes are worthwhile.

Had the public schools been given breathing room, with a moratorium on high-stakes testing that prominent educators urged, resistance to the Common Core would most likely have been less fierce. But in states where the opposition is passionate and powerful, it will take a herculean effort to get the standards back on track.