FORT WAYNE, Ind. (AP) _ Gov. Mike Pence is standing by Indiana's system of assigning “A-F'' grades to schools based on their performance despite reports that former schools chief Tony Bennett oversaw efforts to ensure a top GOP donor's school received an “A.''
 
  Pence told The Journal Gazette that the system is “an essential part'' of accountability measures designed to improve education in Indiana. But he said the public must have confidence that the system is “fair and impartial.''
 
  The Associated Press reported Monday that Bennett and his staff scrambled last fall to change the grading formula so Christel House Academy received an “A.'' Its initial score was a “C.'' 
 
  School founder Christel DeHaan has donated $2.8 million to Republicans since 1998.
 
</span>   Bennett denies the change was directed solely at Christel House.