NEW : Senate Sen. John Cornyn calls for Attorney General Eric Holder to resign or be replaced . NEW : Holder has testified at eight congressional hearings on Operation Fast and Furious , and he has consistently maintained that he knew nothing about the flawed tactics until early last year . Holder tells GOP panel he wo n't resign . A Senate committee says it will consider a contempt measure against John Cornyn . Republicans criticize Holder over ` From the beginning program , probe of classified leaks .
NEW : Senate Sen. John Cornyn calls for Attorney General Eric Holder to resign or be replaced . NEW : Holder tells GOP panel he wo n't resign . A Senate committee says it will consider a contempt measure against John Cornyn . Republicans criticize Holder over ` From the beginning program , probe of classified leaks .