One way Atticus is tough is that he stands up to the mad dog, and shoots it in one shot. Another way he is tough is that he stands up to the mob trying to get Tom Robinson.
Atticus defends his children and the town from the rabid dog Tim Johnson because no one else can shoot as well as he can. Even though Atticus has not shot a gun in thirty years, he faces the dog down.
In a fog, Jem and I watched our father take the gun and walk out into the middle of the street. He walked quickly, but I thought he moved like an underwater swimmer. (ch 10)
His children are surprised that Atticus is a crack shot, and also that he is brave enough to face down the dog. This instance when Atticus is physically brave represents his moral bravery at facing down the rabid dog of racism to protect the town of Maycomb once again.
Atticus also stands up to a mob of angry men who want to kill Tom Robinson. Atticus knows that the mob is coming, so he sits outside Tom’s cell to protect him. Scout notices that the crowd is intimidating.
I thought they must be cold-natured, as their sleeves were unrolled and buttoned at the cuffs. …They were sullen-looking, sleepy-eyed men who seemed unused to late hours. (ch 15)
When the men see Scout and she begins talking to them, it seems to shame them into realizing that they shouldn’t be there and they leave. Scout notices that the men are respectful to her father, even though they are there to lynch his client. They whisper when he asks them not to wake Tom. Atticus stands up to the men despite the physical danger, because he is protecting his client.
Atticus is Maycomb’s moral center. Besides being the town’s legislator and a respected lawyer, Atticus defends Tom Robinson despite the color of his skin, and teaches the town a lesson in morality.