Obama is the first black person ever nominated to run for president.
More from this series
The presumptive US presidential nominees, Senators John McCain and Barack Obama , are looking forward to being confirmed at their parties' conventions.
The race for the White House will then enter its most intensive phase and the candidates and their policies will come under greater scrutiny than ever.
Mike Gallagher finds out what makes these two remarkable individuals tick and explores what their greatest influences have been.
People who know them also have their say about their good qualities and their weaknesses in a two-part series that lifts the lid on the men who would be president.
Programme One - Barack Obama
Senator Obama is the first black person ever nominated to run for president on behalf of a mainstream party, and his racial heritage is a major factor in his politics.
Mike discovers a politician who, as a young man, experienced something of an identity crisis, thanks to his parents' mixed marriage and a childhood split between Hawaii and Indonesia.
The fact that his African father left the family when Obama was very young also had its impact.