Johnson ran for the Democratic nomination in the 1960 presidential election . Although unsuccessful , he accepted the invitation of then-Senator John F. Kennedy of Massachusetts to be his running mate . They went on to win a close election over the Republican ticket of Richard Nixon and Henry Cabot Lodge Jr . On November 22 , 1963 , Kennedy was assassinated and Johnson succeeded him as president . The following year , Johnson won in a landslide , defeating Senator Barry Goldwater of Arizona . With 61.1 percent of the popular vote , Johnson won the largest share of the popular vote of any candidate since the largely uncontested 1820 election
assassinated
Assassination of John F. Kennedy
Lyndon B. Johnson