DENVER  It was the speech of a lifetime for the young presidential candidate: Accepting the Democratic nomination before a sea of supporters outside of the party’s convention hall, and  more critically  addressing concerns of Americans nationwide about his experience level, policy ideas and personal background.

The “New Frontier” speech by John F. Kennedy, as it came to be known, electrified the Los Angeles Memorial Coliseum on July 15, 1960, and it was widely regarded as successfully reassuring voters who were wary because he was 43 years old, Roman Catholic and hardly a legislative lion or foreign policy expert in the Senate.

Of all the echoes of Kennedy’s candidacy that have been noted this year, Senator Barack Obama’s plan for his speech here on Thursday night is one of the clearest. Mr. Obama, anointed by the Kennedy family as an heir to J.F.K., is also leaving the convention hall to deliver his speech  before more than 70,000 people at nearby Invesco Field  and to try to shepherd undecided Democrats and others to his camp.

Image John F. Kennedy, accepting his partys nomination in 1960, sought to ease concern about his religion and experience. Credit... Associated Press

Kennedy, wasting no time, offered a direct challenge to anti-Catholic bias early in his 1960 speech. “I hope that no American, considering the really critical issues facing this country, will waste his franchise and throw away his vote by voting either for me or against me because of my religious affiliation,” he said. “It is not relevant.”