Florida Commissioner of Education, Tony Bennett, resigned on Thursday amid controversy over allegations that he changed the performance grade of a charter school for a Republican donor. Bennett is the former Indiana school Superintendent who promised to hold “failing” schools accountable.

On Monday, the Associated Press reported that they obtained e-mails detailing how Bennett and his staff “scrambled last fall to ensure influential donor Christel DeHaan’s school received an ‘A,’ despite poor test scores in algebra that initially earned it a ‘C.’”

“They need to understand that anything less than an A for Christel House compromises all of our accountability work,” Bennett wrote in an e-mail to then-chief of staff Heather Neal. The e-mails reveal that Bennett discussed with his staff the legality of changing DeHaan’s grade.

Indiana approved the A-F grading system for schools in 2012, calling it a “growth model.” The system received criticism from the start, but its validity has been questioned even further since Bennett’s e-mails surfaced. The system was approved as a replacement for the “No Child Left Behind” law, and determines how much state funding schools receive, among other things.

Bennett took over as Education Commissioner of Florida on January 14 of this year, after he lost his re-election bid for Indiana Superintendent of Public Education in November. Bennett was chosen by the State Board of Education, and the state teachers union was unhappy with his appointment, State Impact reports.

Florida Education Association President, Andy Ford, issued a statement criticizing Bennett’s hiring:

“He is a champion of the testing mania, unchecked expansion of charter schools and voucher programs and has proven to advance the Jeb Bush education agenda that has drawn fire from teachers, parents and experts in the field. That’s the same approach that has led to a flawed and chaotic system in Florida that has frustrated parents and teachers alike.”

According to the AP, Bennett reviewed the e-mails on Monday and denied that he gave preferential treatment to the Republican donor’s school. He estimated that 12 to 13 other schools benefited from the altered grade given to Christel House Academy, yet e-mails show that Christel House was his primary concern and the “catalyst” for change.

Indiana’s then-grading director, Jon Gubera, informed Bennett on September 12, 2012 that Christel House had scored less than an A. That same day, Bennett wrote to Neal saying, “This will be a HUGE problem for us,” to which Neal replied, “Oh, crap. We cannot release until this is resolved.”

Bennett gained notoriety with the help of former Indiana Gov. Mitch Daniels (R), former Florida Gov. Jeb Bush (R), along with a “national network of Republican leaders and donors” including DeHaan. Bennett is a co-founder of Jeb Bush’s Chiefs for Change foundation, which was joined by superintendents across the country advocating for initiatives such as private-school vouchers, merit-based teacher pay, and for-profit online schools.

Gov. Rick Scott (R), who appointed Bennett eight months ago, and former-Gov. Jeb Bush urged Bennett not to resign. “Tony started every day with the focus of creating a system that would equip kids to achieve their God-given potential,” Bush said in a statement. Bennett is the third education commissioner to leave office since Gov. Scott came into office in January 2011.

One Less in Rick Scott’s Den of Thieves, Florida Lt. Gov. Resigns Amid Scandal.

Alisha is a writer and researcher with Ring of Fire. Follow her on Twitter @childoftheearth.