President Barack Obama enters the home stretch of his re-election campaign amid a still-struggling economy, with national polls showing him virtually tied with Republican challenger Mitt Romney.
But Mr Obama has one big thing going for him: voters seem very much to like him personally, and many remain loyal to him even as they give him low marks for his handling of the economy.
If his campaign team can convince his 2008 supporters to flood back to the polls this November, while also persuading undecided voters that Mr Romney does not have their interests at heart, he will win a second term.
Mr Obama, America's first black president, had a turbulent first term in office.
Oratory, charm, background
Barack Hussein Obama made history on 4 November 2008, when he easily defeated Republican rival John McCain to become the first black president of the United States.
Aged 47 when he was inaugurated, Mr Obama was also the first urban president since Harry Truman and the first president born in Hawaii.
And unlike John McCain, George Bush and Bill Clinton, his background was not steeped in the Vietnam War or the cultural conflicts of the 1960s.
Since he took office, the Democrats overcame Republicans' united opposition to pass an economic stimulus programme, overhaul the US healthcare system, lay down new rules for Wall Street and the banking industry, and rescue the US auto industry from collapse.
Later, he and the Democrats overturned a two-decade-old law banning openly gay Americans from serving in the US military. Wielding his presidential authority, Mr Obama also acted without the consent of Congress to grant temporary legal status to some young illegal immigrants brought to the US as children.
Mr Obama despatched a team of commandos to kill Osama Bin Laden, brought the US war in Iraq to a close and struck a new nuclear arms treaty with Russian President Dmitry Medvedev.
Early in his presidency he escalated the US-led war in Afghanistan, and the US has seen a consequent rise in violence there. But Mr Obama has pledged to turn the security mission in Afghanistan over to Afghan troops by the end of 2014, thus ending the more than a decade-long conflict.
Mr Obama was born in 1961 and named for his father, a Kenyan intellectual who met Mr Obama's mother Ann, a white teenager from Kansas, while studying at the University of Hawaii.
When Mr Obama was a toddler, his father abandoned the family and the couple divorced. Father and son were to meet only once more, during a brief visit to Hawaii by the elder Barack Obama.
When Mr Obama was six, his mother married an Indonesian man and the family moved to Jakarta. Then known as "Barry", Mr Obama later moved back to Hawaii, where he was raised largely by his grandparents.
Mr Obama's upbringing in Indonesia, the world's largest Muslim country by population, and his descent from Kenyan Muslims fuelled right-wing conspiracy theories that he was not born in the US, or that he is a secret Muslim.
Mr Obama produced two separate birth certificates to prove that he was born in the US state of Hawaii.
After graduating from Columbia University in New York, Mr Obama worked for three years as a community organiser in poor neighbourhoods in Chicago.
He then attended Harvard Law School, becoming the first African-American president of the Harvard Law Review.
While working at a Chicago law firm, he met Michelle Robinson. The couple married in 1992 and have two daughters, Malia and Sasha; the Obamas are the first couple since Jimmy and Rosalynn Carter to live in the White House with young children.
After Harvard, Mr Obama returned to Chicago to practise civil rights law, representing victims of housing and employment discrimination.
He joined the law faculty at the University of Chicago, where he was lauded as a popular teacher and an exceptional legal thinker.
In 1995 he published his first book, Dreams from My Father, a memoir, and the