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 .
NEW : GOP Sen. John Cornyn calls for Attorney General Eric Holder to resign or be replaced . NEW : Holder tells Senate panel he wo n't resign . A House committee says it will consider a contempt measure against Holder . Republicans criticize Holder over 'Fast and Furious ' program , probe of classified leaks .