Why does Miss Maudie believe that appointing Atticus was no accident?

One day, Scout, Dill, and Jem are visiting with Miss Maudie, their neighbor.  Miss Maudie tells them that "there are some men in this world who were born to do... unpleasant jobs" (To Kill a Mockingbird, Chapter 22).  She notes that Atticus Finch is one of those men.  He has been appointed to defend Tom Robinson, a black man accused of raping a white woman.  

Jem expresses his frustration regarding the Tom...

One day, Scout, Dill, and Jem are visiting with Miss Maudie, their neighbor.  Miss Maudie tells them that "there are some men in this world who were born to do... unpleasant jobs" (To Kill a Mockingbird, Chapter 22).  She notes that Atticus Finch is one of those men.  He has been appointed to defend Tom Robinson, a black man accused of raping a white woman.  

Jem expresses his frustration regarding the Tom Robinson trial.  He questions who will help Tom Robinson.  Miss Maudie notes that many people are supportive of Tom.  She poses a question:

"Did it ever strike you that Judge Taylor naming Atticus to defend that boy was no accident?  That Judge Taylor might have had his reasons for naming him?"

Typically, if the court appoints an attorney for defense in Maycomb, a man named Maxwell Green is selected.  Scout and Jem had not previously thought of this fact.  Green is a new lawyer and has needed to take on more cases to gain experience.  

Miss Maudie knows that Atticus will not win this case.  However, she knows that "he's the only man in these parts who can keep a jury out so long in a case like that."  She knows that Atticus will try his best to give Tom a fair trial even though he is accused of a serious crime for a black man.  He will represent Tom well.  She thinks it is a step in the right direction in the fight against injustice.