Physical Social Movement

There's a lot to be made from Neil's comments on page 90 about physical social movement. Neil remarks, "The neighborhood had changed: the old Jews like my grandparents had struggled and died, and their offspring had struggled and prospered, and moved further and further west, towards the edge of Newark, then out of it, and up the slope of the Orange Mountains, until they had reached the crest and started down the other side, pouring into the Gentile terriotry as the Scotch-Irish had poured through the Cumberland Gap." This physical movement of people on the basis of wealth sets up a decisive barrior between Neil, who lives with his Aunt and Uncle in Newark, and Brenda, who lives with her family outside of Newark. Brenda's parents go a long way to make this barrior even more real with their letters to Brenda after Mrs. Patimkin's discovery of the diaphragm; those letters clearly outline that their is a social gap between Neil and the Patimkin family. Neil goes on to say, "Now, in fact, the Negroes were making the same migration, following the steps of the Jews..." Neil is put in an awkward place because of the physical movements on the basis of wealth; Brenda has already been put on the other side of a stiff border, and even the little boy who comes to the library to admire Gauguin is leaving him behind. What is it that doesn't allow Neil to make the same social migration that the rest of Newark is making?