oh and while the king was looking down the jester stole his thorny crown
Lee Harvey Oswald being the jester who ended the reign of JFK and "stole his crown."
Presley, as the former voice of a more benign kind of alienation and rebellion to the youth of the 1950s, had by this time become somewhat old news, as this generation anointed Dylan their new spokesman. But even as the poet was in the vanguard of the developing shift away from rock 'n' roll's earlier, simpler thematic roots, the jury was still out on the outcome of America's emerging cultural revolution—no verdict was returned. As Dylan emerges as rock 'n roll's new spiritual leader, the thorny crown is an apt symbol; this is perhaps too a picture of the price of fame.
Another interpretation is also suggested at this point in the song, as the King and Queen can now be seen as President John F. Kennedy and the First Lady, with Kennedy’s alleged assassin Lee Harvey Oswald (who even bears a minor physical likeness to Bob Dylan) taking over the role of the court Jester. President Kennedy’s idealism and wit, the First Couple’s youthful vigor and good looks, and the popularity of the Broadway play “Camelot” during these early years of the 1960s inspired the media and the public alike to romanticize the Kennedy presidency as a model of King Arthur’s court. President Kennedy’s assassination in the fall of 1963 by Lee Harvey Oswald could then be seen as the Jester stealing the King’s crown, figuratively robbing him of his authority, but perhaps even going so far as to suggest the crown of the president’s head being blown off by Oswald’s bullet. The "no verdict was returned" would then be referring to the suspicious circumstances surrounding the president’s murder, followed at the end of this verse by the "dirges in the dark" of his national mourning. But even more than the sobering reality of his murder, Kennedy’s death dealt a harsh blow to the nation’s morale, severing the old postwar innocence and optimism and replacing it with a growing cynicism towards American culture and government. With this interpretation, however, the music as the metaphor of change briefly collapses in the song. What is most likely here is that McLean chose these lines to reverberate off other historical events of the period—a tactic we'll encounter again as the song unfolds. But either way, the world the narrator once knew is changing.
Elvis was widely known as the King of Rock and Roll. In 1958, at the peak of his popularity, he was drafted into the army.
When he returned two years later, he started performing ballads, which weren’t as popular with young people. Dylan was more attuned to what was hip, and took the position as the leader of the counter-culture that Elvis had vacated.
McLean refers to this position as a “thorny crown,” an allusion to Jesus, in that this new king is a savior, but also bore a burden.
Dylan faced constant criticism for his decisions, such as “going electric” rather than sticking to acoustic folk. He was supposed to uphold all the expectations of the young generation – such huge pressure!