Kennedy spoke of the future and said he means to be part of it, special words from a man suffering from brain cancer. The Massachusetts senator said he will be in the Senate in January to stand with Obama "when we begin the great test."

He did not speak of the grave cancer he faces but of the things he said he means to do and share. In words echoing those of his brother, President John F. Kennedy, he said that in November "the torch will be passed again to a new generation of Americans.

"The work begins anew. The hope rises again. And the dream lives on," Kennedy said.

His time on stage was brief, little more than seven minutes. But there had been doubt that he would be able to speak at all. He left none, from the moment he stepped to the microphone.

They were minutes of high and unexpected drama for delegates waving thousand of Kennedy signs on opening night of the national convention.

"My fellow Democrats, my fellow Americans, it is so wonderful to be here," he said. "And nothing, nothing is going to keep me away from this special gathering ..."

He flew to Denver Sunday night, and his first stop was a hospital, where doctors examined him. His physicians had been wary of the convention appearance, especially his exposure to crowds, given the weakness of his immune system after weeks of chemotherapy and radiation treatments. The brain cancer was diagnosed after he collapsed in May in Hyannis Port, Mass. After brain surgery in June he had been at home, save for a brief trip to Washington to cast a Senate vote on July 10 for Medicare legislation that had been stalled in deadlock.

It was to have been a Kennedy appearance on tape, after a tribute by his niece, Caroline Kennedy. Instead, he overrode any medical advice to the contrary and came himself.

"I have come here tonight to stand with you to change America, to restore its future, to rise to our best ideals, and to elect Barack Obama president of the United States," he said.

Kennedy's speech would have been standard convention fare, nothing remarkable, but it was a striking performance for man of 76, stricken by cancer. "As I look ahead, I am strengthened by family and friendship," he said. "So many of you have been with me in the happiest days and the hardest days. Together we have known success and seen setbacks, victory and defeat.

"But we have never lost our belief that we are all called to a better country and a newer world," he said. "And I pledge to you, I pledge to you that I will be there next January on the floor of the United States Senate when we begin the great test."

Caroline Kennedy said her uncle "has been a senator for all who believe that the dream has never died." She said "Uncle Teddy" and Obama are "two men who have changed my life and the life of this country.

"Leaders like them come along rarely," she said. "But once or twice in a lifetime, they come along just when we need them the most This is one of those moments."

She said that in this campaign Obama "has no greater champion" than Kennedy. "When he is president, he will have no stronger partner in the United States Senate," she said.