If you prosper through auras and charisma and television magic, then you fade when your image does. Christopher Booker's The Neophiliacs, a study of English society during the Kennedy era, was a good examination of the phenomenon: great collective dreams are created, grow, burst like bubbles and leave a bitter taste behind.
Those who did not live in his time cannot truly gauge his impact, he is only a historical figure not much different than George Washington or William Henry Harrison or Caligula.
But among historical figures some are remembered and some are not. In every generation most are not sure of the current president let alone the record and importance of previous generations. But among the literate? I think Kennedy is still a powerfull voice.
Is that not correct?