Diane Ravitch was ass't Secretary of State (2001-2009) She writes: "William Gumbert has studied the performance of charter schools in Texas, and consistently found that by every measure charter schools are lower-performing than public schools! And yet the GOP who control the state insist on opening more low-performing charters & diverting money from the public schools attended by the vast majority of students. Gumbert says that the charters first promised to improve student test scores; having failed that goal, they now exist to turn public schools over to private corporations. I urge you to open the attached PDF file . It is mind-boggling! Over $30 billion of taxpayer funding later, the Texas legislature and TEA continue to perpetuate the charter movement while 41% of charters have academic ratings of “C”, “D”, or “F” and 86% of school districts have academic ratings of “A” or “B”.