President Barack Obama Re-elected

President Barack Obama has been re-elected to a second term, defeating Republican challenger Mitt Romney. With results in from most states, America's first black president has secured the 270 votes in the electoral college needed to win the race. Mr Obama prevailed despite lingering dissatisfaction with the economy and a well-funded challenge by Mr Romney. Mr Obama's margin of victory is not yet certain because three states have yet to report results. With swing states Virginia and Florida still too close to call, Mr Obama has won 290 electoral votes to Mr Romney's 203. The state of Alaska, where polls have yet to close, is expected to vote for the Republican. Under the US constitution, each state is given a number of electoral votes in rough proportion to its population. The candidate who wins 270 electoral votes - by prevailing in the mostly winner-takes-all state contests - becomes president. The popular vote, which is symbolically and politically important but not decisive in the race, remains too close to call.