What is the theme in The Savage City: Race, Murder, and a Generation on the Edge by T. J. English?

One of the main themes of The Savage City is that of racism. Had racism somehow not been a factor in the happenings of New York City during the 60's and early 70's, things may not have reached the fever pitch they did. As it was, racism was the fuel to the fire in a powder keg situation. When the black communities of the south began migrating north in the 1940's due to the elimination of sharecropping, many Irish, Italian and Eastern European communities of New York City reacted poorly to the influx of "Negroes" into their neighborhoods. Many of the police officers who lived in these neighborhoods found themselves moving further from the city into upstate into predominantly white neighborhoods.