Viola Davis and Meryl Streep lead best actress Oscar

This year's race for the best actress Oscar comes down to two front-runners. Meryl Streep, as Margaret Thatcher in "The Iron Lady," just won the Golden Globe for best actress in a drama -- an award that has predicted seven of the past 10 Oscars. Viola Davis, playing a maid in the deep South in "The Help," just won the Screen Actors Guild award for outstanding leading actress -- which has the exact same track record. So why does Davis have the advantage? Read on.