What is Mr. Dolphus Raymond’s reason for pretending to be drunk when he occasionally comes to town?

Mr. Dolphus Raymond is an enigma to the people of Maycomb. He is a wealthy white man who loves and has a family with a black woman. The couple live in the black section of town and have mixed-race children. Raymond was once engaged to a white woman; however, she committed suicide the night before their wedding. Though the exact reason for her decision is not known, the text suggests it's possible she became aware of his black mistress. Interracial marriages were outlawed at the time the story takes place. In fact, Mayella Ewell even goes so far as to accuse Tom Robinson of rape in order to hide the truth that she expressed sexual interest in a black man.  Because the town of Maycomb cannot understand why Mr. Dolphus Raymond would choose to carry on a relationship with a black woman, which goes against all social and legal norms of the time, Raymond decides to give them an excuse by pretending to be an alcoholic. If he were a low-class citizen like Bob Ewell, then the rest of Maycomb would not care about his life choices. However, Mr. Dolphus Raymond is wealthy and was once well-respected, so his faux alcoholism gives the rest of Maycomb a reason for him to live the way he does. They blame his drinking on the tragedy of his fiancé's death, and his choices thereafter are accepted as a result of the drinking.