In his speech accepting the Democratic presidential nomination, Barack Obama spoke of how his grandmother started as a secretary without a college degree and worked her way up to be a vice president of a bank.

"She's the one who taught me about hard work," he said. "She's the one who put off buying a new car or a new dress for herself so that I could have a better life."

Obama's grandmother, Madelyn Dunham, who turns 86 on Sunday, has been a powerful figure in his life, one he has frequently invoked in his speeches, in his ads and in his memoir.

She is said to be "gravely ill" after falling and breaking her hip, and some reports suggest she might not live to see the results of the Nov. 4 election. Obama, with just two weeks left to go in his quest for the presidency, will suspend his campaign to fly to her bedside Thursday.

David Mendell, who interviewed Dunham in 2004 for the Chicago Tribune, said Obama got "that dreamer quality" from his late mother. But when he has to decide whom to trust in politics, "that's his grandmother's practicality coming out in him."

It will be the second time since August that Obama has put his campaign on hold to go to Hawaii, where he grew up. While on a vacation, he visited Dunham, whose osteoporosis prevents her from traveling, at her apartment in Honolulu nearly every day.

Some supporters worry that the temporary suspension of his campaign will cost him precious time on the campaign trail. But Obama may be troubled by the painful memory of his mother, Ann Dunham, who died of ovarian cancer in 1995.

"The biggest mistake I made was not being at my mother's bedside when she died," Obama said in 2004. "I didn't get there in time."

NEW YORK TIMES, ASSOCIATED PRESS