Jay Mathews writes a regular blog about education for the Washington Post. He has been writing about education for decades. His most recent book celebrates KIPP. He has been the guiding force behind the idea of ranking high schools by the number of students who take AP courses. One of the things I like best about him is that he changes his mind when the evidence changes. He gets enthusiastic about big ideas, but is willing to step back if he thinks he was wrong.

In this remarkable column, Mathews explains the allure of the Common Core, the idea that all children will be measured by the same yardstick. But then he interviews Tom Loveless of Brookings. Loveless is a Common Core skeptic. He analyzed performance in states with high standards and low standards and concluded that the standards–no matter how rigorous and uniform they are–won’t make much difference.

Mathews is persuaded that the Common Core will eventually fade away, as teachers and policymakers realize that they don’t live up to the hype.