In Maniac Magee by Jerry Spinelli, why doesn't Jeffrey go back to the McNabs' house?
Jeffrey leaves the McNabs because they are racist and he is unable to make them see that color does not matter.
Jeffrey takes the McNab twins home, and their brother is not happy to find out that the boy who rescued them is the one who made a fool of him by blasting his fastballs “to smithereens.” Maniac is not at all comfortable in the McNab house.
Maniac had seen some amazing things in his life-time, but nothing as amazing as that house. From the smell of it, he knew this wasn't the first time an animal had relieved itself on the rugless floor. In fact, in another corner he spotted a form of relief that could not be soaked up by newspapers. (Ch. 35)
Worse than the uncleanliness is the disorder and the Cobras, who are basically white supremacists and unpleasant to be around. These people do not share Maniac’s worldview. Maniac stays because he is trying to convince little Piper and Russell to stay in school.
One night, Maniac finds himself in the West End at the Beale House, and everyone is thrilled to have him there. He has a great time, and feels like he is home. He only gets to leave by sneaking out.
Jeffrey’s attempt to bring Mars Bar into the McNab house to bring the races together backfires. You can't fix race relations overnight. He realizes it was foolish to think that it would work, and he once again leaves.
Maniac stopped. He had been walking in circles. It was dark. He turned one way, then another, for the briefest moment thinking to go home. Thinking, it's time to go home now. Then remembering that once again he had no home to go to. (Ch. 42)
Maniac never felt as comfortable with the McNabs as he did with the Beales. Eventually, that is the only family he has and the only one he can go back to. He knows that they will always welcome him with open arms. Color has nothing to do with it.