MIAMI - Florida's Democratic Party declared victory for US President Barack Obama in the closely divided battleground state on Thursday, as he clung to a narrow but apparently insurmountable lead in the glacially slow tallying of votes.

If Obama wins Florida, it will add to his Electoral College margin and he will have won all of the key US swing states.

"On behalf of Florida Democrats, I wish President Barack Obama congratulations on his re-election and on his winning Florida's 29 electoral votes," Rod Smith, chairman of the Florida Democratic Party, said in a statement.

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