Almost a year before the first votes of the 2020 -presidential contest, Democratic candidates are all over the map. There’s Elizabeth Warren in a drafty warehouse in Des Moines, Iowa, boasting to more than 1,000 people about forcing out a bank CEO. In South Carolina, Cory Booker’s in a college auditorium bringing the crowd to tears with his tale of the murder of a young boy from the Newark, N.J., projects. Sherrod Brown’s in an Ohio union hall, wondering in his raspy baritone if his party has lost touch with Middle America.