How is atticus weak?

If you are referring to "To Kill a Mockingbird", no, Atticus does not act feeble. He is honest, kind, fair and gentle. He is also intelligent and because he does not pontificate or go into dramatic rages, he is not weak. But he plays by the rules to the best of his abilities and has found himself in a situation where justice is not going to prevail against prejudice and ignorance. How does anyone handle that kind of situation?