Oprah Winfrey has officially thrown her support behind U.S. presidential candidate Barack Obama, after joining the Democrat senator at a campaign rally in Iowa on Saturday (08Dec07). The talk show queen recently revealed her plans to back Obama as her choice to replace President George W. Bush when America goes to the polls next November (08). Winfrey told the crowd at Saturday's rally at the Iowa Events Center in Des Moines: "This is very, very personal. I'm here because of my personal conviction about Barack Obama and what I know he can do for America. "For the very first time in my life, I feel compelled to stand up and speak out for the man who I believe has a new vision for America. I believe that Barack Obama will bring statesmanship to the White House. I believe that he will lead with strength, conviction, honour and compassion."