What is the theme in The Quiet Game by Greg Iles?

Racism is prevalent in THE QUIET GAME by Greg Iles, and a central theme to the novel. Based in Natchez, Mississippi in 1998, The Quiet Game revolves around the supposed racial murder of Delano Payton, a black man who had gotten a promotion at the Triton Battery plant in 1968. Payton had been blown up in his car, and the common thought at the time and until recently had been that the murder was in retaliation for Payton taking the job that "belonged" to a white man. Payton had been active in the Civil Rights movement, and with the Ku Klux Klan active in the area at the time, this seemed to be a natural assumption.