What kind of case was Atticus referring to when he told Jack you were hoping to get through life without a case of this kind?

Atticus was referring to a kind of case with a tremendous furor, he knew it will be like that, everybody will insult him for being such a "Negro Lover." But he didn't mind, he just went with his values and beliefs because he has a moral, unlike to those people, he know that those black persons are people TOO. He wouldn't want Jack to get to messy in such kind of case.