On Saturday, Democrat Julian Castro held an event in his hometown — San Antonio, Texas, where he served as mayor for five years — to announce he is running for president. But Castro’s campaign might be a bit a of a long shot considering he’s polling between 0 and 2 percent in state and national polls. That said, he has all the makings of an inspirational candidate — he’s young and ambitious, he overcame a childhood of poverty to attend Stanford and Harvard Law, and if he wins the nomination, would be the first Latino presidential nominee on a major-party...