chicago president barack obama friday cast ballot nov. election trip hometown chicago onlookers cheer obama u.s. senator illinois prior become president enter early-voting facility downtown chicago smile obama shake hand poll workers site thank outstanding work head electronic vote machine see obama ask workers jokingly shield machine reporters stand nearby obama campaign democratic nominee hillary clinton succeed oval office 2012 obama first president vote early time run second term white house obama schedule spend weekend chicago make stop vote facility appearances two political fundraisers obama cast early vote 2016 election chicago trip