Kennedy would be 91 had he lived; King would be 79. That means tens of millions of Americans have only dim youthful memories of either one, or weren't yet born. You have to be over 65 to have experienced them as an adult. Maybe it's not so surprising that older white Democrats strongly preferred Hillary Clinton to Obama, and older African-Americans did so at first. They could make the personal comparisons with their heroes more easily, and found Obama wanting. Other seniors describe themselves as moved by a politician for the first time in four decades and tell reporters at rallies that Obama reminds them of Kennedy or King.

Their children and grandchildren know these figures only from history books and documentaries. Obama appeals to them through a kind of imaginative nostalgia. This longing for an emotion they never experienced, but feel they missed, is part of what brings them out in such numbers at his events. Having come of age in the '70s, '80s or '90s, they see Obama not only as a ticket to the future, but a means of transporting them across the years to a mythic past, where politics could be a force for good. Those who predicted he would prove merely a fad neglected the power of generational envy on the part of those who were too young for the 1960s.

Every time Obama evokes JFK or MLK, his critics come out of the woodwork to trash the comparison. Kennedy served 14 years in the House and Senate before becoming president, they say. That's much more experience than Obama's four years in the U.S. Senate. To even speak of Obama in the same sentence as King is, for them, ridiculous.

Of course African-American voters don't feel this way. Nor do most of the people who actually knew Kennedy and King and worked with them. Ted Sorensen, who was JFK's top aide, was an early Obama supporter and thinks the comparison is apt. So does former senator Harris Wofford, Kennedy's aide on civil rights, who believes Obama could make a superior president to JFK. Ted Kennedy has said Obama reminds him of his brother, a compliment he has offered no other politician in more than four decades. King's aides were slower to come around to Obama; many were Hillary Clinton supporters. But most are now enthusiastically for Obama, even if they feel a bit jealous of him.

It's a mark of Obama's supreme confidence in his own destiny that he welcomes comparisons not just to Kennedy and King but to Lincoln. If he loses, the comparable candidates will be more along the lines of John Kerry and Michael Dukakis, who both blew leads, and Al Smith, who lost as the first Roman Catholic nominee in 1928. If he wins but fails as president, Jimmy Carter will come to mind. If he succeeds with a bold agenda, FDR and LBJ will get some ink. But behind the immediate analogies lies a more potent image, one ripe for disappointment but tantalizing all the same: It's Jack Kennedy and Martin Luther King morphing into a single leader, a vessel for the deferred dreams of Democrats. That's the plan, anyway. We'll see if it works on Aug. 28 in Denver.

© 2008