The Associated Press says that a high turnout among African-American voters was a decisive factor for U.S. President Barack Obama’s successful reelection last year.

Based on its analysis of last year’s census data, turnouts and exit polls, the AP said that Obama won the reelection thanks to African-American voters’ support.

The news agency said that Republican candidate Mitt Romney would have beaten Obama by a narrow margin if the turnout among African-American voters had been low as in 2004.

The overall turnout in last year’s U.S. presidential election stood at 58 percent, down four percentage points from 62 percent in 2008 when Obama was elected as the U.S.' first African-American president.