Why does Dolphus Raymond sit outside during the trial?

To keep up the façade of being a drunk who has taken a black mistress and has fathered mixed children, Dolphus Raymond isolates himself from the other white citizens of Maycomb by playing a role.  He truly cares about the outcome of the trial; however, he doesn’t risk being found out that he isn’t a drunk so he can still fit in as much as possible in the white community.  Dolphus Raymond hates the racism...

To keep up the façade of being a drunk who has taken a black mistress and has fathered mixed children, Dolphus Raymond isolates himself from the other white citizens of Maycomb by playing a role.  He truly cares about the outcome of the trial; however, he doesn’t risk being found out that he isn’t a drunk so he can still fit in as much as possible in the white community.  Dolphus Raymond hates the racism he sees dictate the values and beliefs of the Maycomb town folks.  He tells his feelings about race when he comments on the plight of blacks in the community to Scout and Dill.  He tells them about “ . . . the hell white people give colored folks without even stopping to think that they’re people too.”

There is also the possibility that because of his relationship with his black mistress, he may know Tom Robinson.  Although it is never mentioned, his appearance at the trial perhaps suggests that he also has a personal interest in the outcome.  In addition, Raymond may not feel comfortable sitting in the white section of the courthouse.  There is a possibility that he will be ostracized by the other people attending the trial. 

Overall, Raymond is a sensitive, caring man who navigates two worlds, a black one and a white one. Raymond’s interest in the trial probably stems from his loathing for the racism in Maycomb that keeps him pretending to be something he is not. He also hates how blacks are treated in the community. He also has an interest in whether or not Atticus can get Tom off for the crime.  He feels that Atticus is the best man for the job, and Raymond wants to witness the trial but does not want to experience the racist testimony of Bob and Mayella Ewell that eventually leads to the jury passing down a guilty verdict.