Robert Kennedy had been Attorney General during his brother's Administration. He stayed in that position for the first nine months of the Johnson Administration but finally resigned to run to become a Senator from New York. He served as a New York Senator starting in January
1965. In 1968 Kennedy had given thought to oppose President Johnson attempt to be reelected but had rejected the idea. After Eugene McCarthy came close to defeated Johnson in the New Hampshire primary Kennedy decided to run. He declared his candidacy on March 16, 1968. President Johnson shocked the nation when on March 31 he announced he would not run.

Kennedy entered and won the Indiana and Nebraska primaries but lost the Oregon primary to Eugene McCarthy. The California primary was going to be key, and on June 4th Kennedy won the primary there. Shortly after midnight on June 5th Kennedy addressed his supporters in the ballroom of the Ambassador Hotel in Los Angeles. As he left through the hotel kitchen Sirhan Sirhan and 24-year-old Palestinian shot Kennedy three times. Kennedy died in the hospital the next morning. He was 42 years of age.