http://www.YouDecide2008.com - Oprah Winfrey speaks at a Barack Obama campaign rally in Des Moines, Iowa from Hy-Vee Hall at the Iowa Events Center. Part 2: http://www.youtube.com/watch?v=iTCWgljr8tY More info: DES MOINES, Iowa (CNN) — Political endorsements rarely translate into votes, but sometimes the timing of one can carry great significance. That's what Sen. Barack Obama's campaigners hope for as they pick up the backing of Oprah Winfrey less than one month from the Iowa caucuses. The three-state "Oprah-bama" tour starts at a Des Moines, Iowa, rally Saturday in a space that can accommodate thousands. It then moves east to Cedar Rapids for an event expected to bring in close to 8,500 people.