Why is Mr. Underwood's editorial defending Tom Robinson surprising?

In
,reads Mr. Underwood's editorial regarding Tom Robinson's unfortunate, tragic death. Scout
mentions that Mr. Underwood was at his most bitter when he likened Tom's death to the
"senseless slaughter of songbirds." Mr. Underwood expresses his belief that it is a
sin to kill cripples in his editorial, and he also illustrates a change of heart regarding race
relations.had mentioned that Mr. Underwood was a racist man, who couldn't stand being around
black people. Mr. Underwood is even named after a Confederate general and views the Finch
children with contempt for sitting in the Negro balcony during the trial. However, Mr. Underwood
seems to have changed his stance regarding his black community members by sympathizing with Tom
Robinson following the trial. Mr. Underwood's article essentially defends a black man, which is
unlike his character and reveals his change of heart. After reading Mr. Underwood's article,
Scout fully understands the dangers of prejudice and the harmful effects of racial
injustice.