What is the main conflict in Robert Kennedy and His Times by Arthur Meier Schlesinger?

Arthur Schlesinger, Jr., biographer and actual friend of RFK, chronicles the life of Robert “Bobby” Kennedy, brother to United States President John Kennedy. This detailed two volume biography is the quintessential read about Robert Kennedy as it ranges from his childhood through his political and administrative career as an Attorney General, a Senator and his 1968 Presidential bid and concluding with his assassination on the night of his win at the Democratic primary.