Why does Atticus say that the law is strict for common people, but bent in some ways for Ewells?

The rules are somewhat bent for the Ewell family.  They are very poor, and the only government checks that Bob Ewell gets he spends on alcohol.  So, he is allowed (even though it is illegal) to hunt and trap out of season.  Atticus tells Scout that all of the farmers and land owners of Maycomb county agree that those kids need some sort of food, so anything he can hit, they allow him to in order to feed those kids.

Another thing that is different about the Ewells is that they only have to go to school for one day.  They are made to go that first day, but after that, the Tardy Lady doesn't bother them anymore.  They are such a poor family, and according to Atticus, "they live like animals." Most of the families don't want them in school with their kids, so they just let them get away with skipping school.