INDIANAPOLIS — Indiana’s A-F school grading system faces scrutiny over emails showing that education leaders scrambled to overhaul the program at least in part to ensure that a prominent Republican donor’s charter school received a top mark.

The September 2012 emails obtained by The Associated Press show former schools Superintendent Tony Bennett urging his staff to find a way to give Christel House an A grade despite poor test scores in algebra that earned it a C.

The grades help determine school funding and even how teachers are compensated. The system is part of a sweeping education overhaul Bennett launched in Indiana that made him a star in conservative circles.

Bennett says the grading overhaul wasn’t directed solely at Christel House.

Bennett was elected Indiana’s Superintendent of Public Instruction in 2008 but was defeated in his re-election bid last year by Democrat Glenda Ritz.

Before his election, Bennett was a longtime southern Indiana educator. His roles included a stint as superintendent of Greater Clark Schools and assistant superintendent for New Albany-Floyd County schools.

 Bennett is reviewing Florida’s grading system as that state’s education commissioner.