Why does Dolphus Raymond hide Coca-Cola in a brown paper bag?

Dolphus Raymond, a white man who prefers the company of African Americans, uses a brown paper bag as a theatrical prop to act like a drunkard. He has mixed-race children and lives among the African American community as one of them. During the trial, when Dill feels sick, Mr. Raymond explains to Scout and Dill that he pretends to be drunk all the time so that people can explain away his behavior. “It helps folks if they can latch onto a reason,” he says. He admits that he even staggers sometimes to reinforce his charade.