Poll workers check the identification of a voter in the tiny precinct of Smith Creek
US President Barack Obama's top aide in Florida said Democrats have won the vote in the officially undeclared Sunshine State, where officials are under fire for mishandling the ballot.
Obama in the end did not need the biggest swing state as he won enough states across the country to romp to a decisive electoral college victory in Tuesday's election, but his team believes they triumphed in any case.
"On behalf of Florida Democrats, I wish President Barack Obama congratulations on his re-election and on winning Florida's 29 electoral college votes," Florida Democrats chair Rod Smith said in a statement Thursday.
In the 2000 presidential election, the close Florida race led to a weeks-long standoff that was eventually decided by the Supreme Court, which ruled in favor of George W. Bush despite his losing the nationwide popular vote.
Mitt Romney's senior campaign adviser in Florida hinted earlier that the Republican presidential challenger lost the state, where the result has yet to be announced more than two days after the election.
Electoral officials have said all vote returns must be completed no later than Saturday, but the statement from Romney's campaign published in the Miami Herald suggested his team had already accepted defeat.
"The numbers in Florida show this was winnable. We thought based on our polling and range of organization that we had done what we needed to win," senior campaign adviser Brett Doster said in the statement.
"Obviously, we didn't, and for that I and every other operative in Florida has a sick feeling that we left something on the table," he added.
Obama campaign manager Jim Messina said he was confident the president would be declared the victor.
The campaign's voter model continues to show that Obama "will hold that lead and end with 332 electoral votes," Messina said.
In the state-by-state electoral college system, 270 votes are needed for victory, and Obama already has 303, with Florida's 29 still outstanding.
Votes are still being counted in three of Florida's 67 counties, said Chris Cate, a spokesman for the state government. "Counties are required to report their results to us by Saturday at noon," he told AFP.
In 2000 Democratic Vice President Al Gore, who won the US popular vote, lost the election to Bush, who triumphed under the electoral college system when a divided US Supreme Court stopped a ballot recount in Florida.
Republicans control both houses in Florida's state legislature and the governor's mansion, but a growing Hispanic and more liberal population are pushing the electorate toward Obama's Democrats.
Florida Deputy Elections Supervisor Christina White blamed the vote count delay on an unusually long ballot and a high voter turnout.
"It's not that there were any problems or glitches. It's about volume and paper left to be processed," she said.
But at least two Florida vote experts saw the chaos as the result of a bare-knuckled Republican attempt to suppress turnout.
Lance deHaven-Smith, of Florida State University, said the count was running late because "an entrenched Republican political class is trying to fend off a rising tide of Democratic voting."
Republican state officials have been "intentionally under-supplying voting places and equipment" to create bottlenecks in traditionally Democratic strongholds, he said.
Charles Zelden, a history and law professor at Nova Southeastern University in Florida, said the southern state's Republican legislature wanted to dampen the vote for partisan purposes.
He pointed to a law signed last year by Governor Rick Scott reducing the number of early voting days from 14 to eight and eliminating early voting on the Sunday before election day.
Democrats tend do better in early voting.
"The blame," Zelden said, "lies with the fact we allow the partisans to run our elections."
Voting in the United States is "controlled by the states, which are run by politicians with partisan objectives. Hence the problems," he added.