In a spate of campaigning organised at the 11th hour, Vice-President Dick Cheney was arriving on Sunday for a lightning visit to mobilise Republicans before Tuesday's election.
Meanwhile, the Democrats have sent former vice-president Al Gore and Alexandra Kerry, daughter of their presidential nominee, John Kerry.
Hawaii, known better for bright shirts than for heavyweight politics, is normally below the campaign radar as races are often decided by the time the polls close in the islands and few candidates want to spend vital campaign time travelling all the way to the islands for just four electoral votes.
The last candidate on a presidential ticket to campaign in Hawaii was Richard Nixon when he was running for president in 1960.
But the 2004 campaigns decided to bring the tropical state in from the cold when polls last week showed that President George Bush could win the traditionally Democratic stronghold.
Kerry sent his daughter to attend
a concert in the tropical state
A poll by The Honolulu Advertiser, the state's largest newspaper, found Bush and Kerry even among likely voters with about 12% of voters undecided. A poll by the Honolulu Star-Bulletin and local TV station KITV found Bush leading by 1 percentage point.
In response, the Democratic National Committee began running local television ads and former president Bill Clinton gave interviews to Hawaii's TV stations.
Gore and Kerry's daughter attended a high school concert on Friday in a working-class neighbourhood.
"That's how desperate this thing is. That's how close this thing is," Dan Boylan, a political analyst and history professor at the University of Hawaii-West Oahu, said. "And everybody has money, so they can afford to come here."
Boylan said he did not think Hawaii's voters would be swayed by the attention. "But it does energise the supporters of both candidates and energise them to work that much harder to get out the vote," he said.
Republican presidential candidates have prevailed only twice in Hawaii since statehood in 1959 - Nixon in 1972 and Ronald Reagan in 1984, both of them landslides.
But since 2002, when Linda Lingle became the first Republican governor in 40 years, Hawaii Republicans have felt rejuvenated.
president has won
re-election unless he's won Hawaii and we'd
like to continue that"
Brennon Morioka, Hawaii Republican Party chairman
This year they feel inspired, said Brennon Morioka, chairman of the Hawaii Republican Party.
"The fact that the race nationally will be so close that every electoral vote will count and Hawaii has such a tight race puts Hawaii in play as a pivotal state that could cast the deciding vote to put the winner on top," Morioka said.
"No Republican president has won re-election unless he's won Hawaii and we'd like to continue that."
Brickwood Galuteria, chairman of the Hawaii Democratic Party, said he thought Kerry would win the state.
The campaign visits and the tight race put the state on a national stage, Galuteria said, adding that the weekend hoopla will be "one of the most politically explosive weekends in the state's history".
"Our four electoral votes become very important all of a sudden."