Robert F. Kennedy presidential campaign began on March 16 , 1968 , when Robert Francis Kennedy ( RFK ) , a U.S. Senator from New York who had won a Senate seat in 1964 , entered an unlikely primary election as a challenger to incumbent Democratic President Lyndon B. Johnson ( LBJ ) . After Johnson announced on March 31 that he would not seek re-election , Kennedy still faced two rival candidates for the Democratic Party 's presidential nomination : the leading challenger Eugene McCarthy and Vice President Hubert Humphrey . Humphrey had entered the race after Johnson 's withdrawal , but Kennedy and McCarthy remained the main challengers to the policies of the Johnson administration . During the spring of 1968 , Kennedy campaigned in presidential primary elections throughout the United States . Kennedy 's campaign was especially active in Indiana , Nebraska , Oregon , South Dakota , California , and Washington , D.C. . He had been making progress in building Democratic support for his nomination when he was assassinated in Los Angeles on June 5 , 1968
assassinated
Assassination of Robert F. Kennedy
Robert F. Kennedy 1968 presidential campaign