According to the second quote at the beginning of chapter 6, what "habit" has been slowly brought into Dawson's Landing? How?

The quote reads,

"Habit is habit, and not to be flung out of the window by any man, but coaxed downstairs at step at a time."

Twain uses the story of Luigi and Angelo Capello's childhoods to once again highlight the arbitrariness of racial classifications. The twins recount how they were essentially sold into slavery as children to pay off their parents' debts. They were forced to work and perform without compensation, and even had to beg for food. So, the town must very slowly grapple with the distinction between these white Europeans and the blacks they consider slaves.