What is the importance of Dallas, Texas in the book, Killing Kennedy?

Dallas, Texas is the city in which President John F. Kennedy was killed along with Texas governor John Conally. Texans, by and large, were not fans of the Kennedy administration even though Lyndon B. Johnson had been a Texas rancher. The Civil Rights movement further tarnished JFK's image in the minds of the southerners. Even JFK referred to Dallas (and perhaps Texas as a whole) as "nut country."