Barack Obama wins US Presidential election for the second term as 44th President after winning a key victory in Ohio
President Barack Obama has re-elected on Tuesday as Mitt Romney's struggled to win vital swing state.
Obama was projected the winner in the Democratic strongholds of New York, New Jersey, Maryland, Vermont, Connecticut, Delaware, Massachusetts and his home state of Illinois, as well as Washington, DC.
At least 120 mn American voters were expected to decide between the Democratic incumbent and Romney after a long, expensive and bitter presidential campaign centered around.
In the state-by-state battle to get to 270 electoral votes needed for the presidency, Obama and Romney piled up early victories in the states they were expected to win easily.
"This happened because of you. Thank you," Obama tweeted to his 22 million followers on Twitter as a flurry of states.
With a clutch of swing states, including Florida and Virginia still to be declared, Obama already had 275 electoral votes, more than the 270 needed for the White House and looked set for a comfortable victory.
Romney led in the national popular vote with 40 mn votes, or 50 per cent, while Obama had 34.4 million, or 48 per cent, with half of the precincts tallied.
But Obama led in the competition for electoral votes. He led 234-200, with 270 required for victory.
President Obama need to address a so-called fiscal cliff of more than $600 bn in tax increases, unless Congress can reach a budget compromise.