In the pages of his best-selling memoir, Hillbilly Elegy, Sen. J.D. Vance (R–Ohio) uses his life story as a model for how the children of down-on-their-luck Americans from outside the country’s political and cultural power centers can find success. It is, sincerely, a compelling personal story. One that Vance retold in vivid detail to cap the third night of the Republican National Convention (RNC) in Milwaukee. He got out of his childhood home of Middletown, Ohio—”a place that had been cast aside and forgotten by America’s ruling class in Washington,” he said—to join the Marines, attend colleg…