 Grassley says Trump was an unproven political commodity when he first announced his run for president in 2015. He says many people were like Vance, doubting whether Trump could do the job until they saw what he did as president. 27-year-old Joe Mitchell of Des Moines, the youngest Iowa delegate at the Republican National Convention. He's a former state legislator who took the office at 21. He says Vance will appeal to younger voters. He says things are beginning to snowball for Trump right now.