impression is that iowans make up their minds late, and they change, and the front-runner ends up getting behind, and the front-runner comes back. i'm running to win. i'm not running to lose. i'm not running to come in third or fourth or fifth or anything like that. so i feel good about it. >> reporter: biden will continue on with his bus tour with two stops on monday, all in an effort to try to meet as many voters as possible. his campaign told me the more time biden spends one-on-one with voters, the better it will be. i talked to several voters who came undecided. some walks away undecided but others came away leaning towards the former vice president. arlet arlette saenz, storm lake, iowa. joe biden is one of 17 people running for the democratic nomination. there's one person who could help narrow down that field. former president barack obama. but as dana bash reports, he's not making any endorsements.