U.S. Democratic presidential candidate, Senator Barack Obama (D-IL) is joined by entertainer and talk show host Oprah Winfrey (R), and his wife Michelle, as they acknowledge participants at a rally in Des Moines, Iowa. December 8, 2007. Iowa holds the first-in-the-nation caucuses for the 2008 Presidential election on January 3. REUTERS/Jason Reed (UNITED STATES)