In call to action, Kennedy puts the Camelot trust in Obama

DENVER - Before Ted Kennedy electrified the Democratic National Convention last night, most of the audience was unsure whether he would speak at all.

And when the surprisingly robust Kennedy took the stage, his hair thinned by cancer treatments and his face bloated from anti-seizure medication, the audience girded itself for an emotional outpouring.

But Kennedy's speech was much more than a moving acknowledgment of the tribute being paid to him - it was much more than anyone could have expected. It was, in fact, the party's real keynote address - a call to arms that brought together past and present, and set the agenda for all the speeches to follow.

Kennedy's accomplishments were many.

He reminded Democrats that healthcare - not energy or war - is their defining issue, declaring for posterity that "this is the cause of my life" and insisting that access to medical treatment must become "a fundamental right."

He established a tone of aspiration and high principle for all the speakers who followed, reminding a new generation of voters that his brother challenged America to go to the moon, and that "today an American flag still marks the surface of the moon."

He also - and perhaps most importantly - bequeathed the "dream" of charismatic liberalism that was embodied by President Kennedy to Barack Obama; with the martyred president's daughter at his side, he made it clear that Obama, more than any member of the Kennedy family, would be the future custodian of the Camelot legacy.

Though Kennedy made only oblique references to his brain cancer, and promised to be in the Senate in January to lead the healthcare fight, his intention to put the Kennedy trust in Obama's hands was as visible as if he had signed a last will and testament.

"And so with Barack Obama - for you and for me, for our country and for our cause - the work begins anew, the hope rises again, and the dream lives on," Kennedy concluded, in remarks that echoed his brothers' words and his own.

While Kennedy's illness provided the emotional backdrop for the speech, the presence of Obama on the top of the ticket also made the remarks more resonant, because Obama has sought to reconnect two strands of the Kennedy legacy that had diverged in recent decades.

At recent Democratic conventions, candidates have cited President Kennedy as their inspiration, the way that Ronald Reagan is now routinely invoked as the spiritual leader of the Republican Party.

But Ted Kennedy, still hard at work in the trenches of the Senate, served a different function. His speeches were slotted in as partisan calls to arms, useful to rally the party's core, even as his very presence as a struggling foot soldier in the cause of liberalism made hope seem more distant.

If President Kennedy represented an idealized past, Ted Kennedy represented an unfulfilled future.

With an aspirational figure at the top of the ticket, however, Democrats can hope that the work in the trenches and the words on the podium may finally be aligned.

For even though recent Democratic nominees have paid homage to President Kennedy, they haven't tried to match his sense of high purpose. Not Michael Dukakis with his call for "competence, not ideology." Not Bill Clinton, who focused on concrete, modestly attainable goals. Not Al Gore, who embraced a populism that pitted "the people" against the powerful. Not John Kerry, who dwelled on his readiness to command the military.

In little more than 500 words, Kennedy reminded his audience that purpose and progress can go hand in hand and that the hope of the past can be the hope of the future.

His own passage through history gave emotional resonance to the speech, but he also performed a necessary function: He introduced the Democratic Party to its nominee.

Peter S. Canellos is the Globe's Washington bureau chief.