WEST PALM BEACH, Florida // Democratic presidential candidate Barack Obama is cancelling nearly all his campaign events Thursday and Friday to visit his suddenly gravely ill 85-year-old grandmother in Hawaii, a spokesman said. Robert Gibbs told reporters aboard Mr Obama's plane last night that Madelyn Payne Dunham, who helped raise Mr Obama, was released from the hospital late last week. But he said her health had deteriorated "to the point where her situation is very serious." Events originally planned for Madison, Wisconsin, and Des Moines, Iowa, on Thursday will be replaced by one in Indianapolis before he makes the long flight to Hawaii. On Friday, Mr Obama's wife, Michelle, will sub for Mr Obama at rallies in Akron and Columbus, in Ohio, said campaign spokeswoman Jen Psaki. Mr Obama was expected to resume campaigning on Saturday, at an undecided location in the West, she said. "Sen. Obama's grandmother, Madelyn Dunham, has always been one of the most important people in his life, along with his mother and his grandfather," Mr Gibbs said. "Recently his grandmother has become ill and in the last few weeks her health has deteriorated to the point where her situation is very serious. It is for that reason that Sen. Obama has decided to change his schedule on Thursday and Friday so that he can see her and spend some time with her." Citing the family's desire for privacy, Mr Gibbs would not discuss the nature of Ms Dunham's illness. It seemed likely that she was close to death, as Mr Gibbs said that "everyone understands the decision that Sen. Obama is making." Ms Dunham turns 86 on Sunday. It could be a momentous decision in Mr Obama's bid for the White House against Republican John McCain, with Election Day just two weeks away on Nov. 4. In a campaign ad this year, Mr Obama described Ms Dunham as the daughter of a Midwest oil company clerk who "taught me values straight from the Kansas heartland" - things such as "accountability and self-reliance". "Love of country. Working hard without making excuses. Treating your neighbour as you'd like to be treated." She is also the "white grandmother" he referred to in a speech on race. Mr Obama recognised Ms Dunham when he accepted the Democratic presidential nomination at the party's convention in Denver. "She's the one who taught me about hard work. 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. She poured everything she had into me. And although she can no longer travel, I know that she's watching tonight, and that tonight is her night as well," he said. Mr Obama last visited Hawaii in August for a week's holiday after he had clinched the nomination.