Diane Ravitch, a former assistant secretary of education, spent years advocating for an overhaul of the American education system. She supported the No Child Left Behind Act, the charter school movement and standardized testing.
But Ravitch recently — and very publicly — changed her mind. She looked at the data and decided that the kinds of changes she'd supported weren't working. Now she's a prominent critic of things like charter schools and school choice — and she's particularly opposed to privatizing schools.