An aide to U.S. Democratic presidential candidate Barack Obama says he will suspend his campaign later this week in order to travel to Hawaii to visit his grandmother, who the aide says is gravely ill.

Campaign officials said late Monday that Obama is canceling most campaign events Thursday and Friday to visit Madelyn Dunham, 86, who helped raise him.  Officials said Dunham's condition has deteriorated to the point where her situation is serious.

Earlier Monday, Obama and his opponent John McCain appealed to voters in key states as their campaigns entered the final two weeks leading up to the general election.

Obama campaigned Monday in Florida, a populous state in the southeastern U.S. that would give either candidate a significant push towards the White House.  On Monday evening, he and Senator Hillary Clinton, his former rival for the Democratic nomination, appeared together in Orlando.

The pair urged supporters to vote and cautioned against overconfidence.  Most public opinion surveys show Obama leading Republican McCain by about five percentage points.  Obama criticized McCain's campaign tactics, accusing him of resorting to personal character attacks.

McCain campaigned Monday in the closely contested midwestern state of Missouri.  His vice presidential pick, Sarah Palin, held a rally in the western state of Colorado. 

Both Republicans emphasized their aims to cut business and capital gains taxes, carry out plans to keep Americans in their homes, and help protect retirees' investments.  

McCain is scheduled to appear later Tuesday in another battleground state, Pennsylvania.  Obama and Hillary Clinton will continue their joint appearances at other locations in Florida. 
