Barack Obama has won the 2012 presidential election, overcoming a determined challenge from Mitt Romney and the worst election-day unemployment rate since World War II.

For the 51-year-old Democratic incumbent, gaining a second term during a weak economic recovery proved even more difficult than his historic selection as the nation's first African American president.

The reelection drive bore only a faint resemblance to the 'hope and change' campaign that brought him to power in 2008, a time of deepening financial crisis and voter dissatisfaction after eight years of a Republican administration in Washington..