 Allison Poley at the Wall Street Journal on vacation home swappers. Donald Trump has announced that Ohio Senator J.D. Vance will be his running mate in the race for the White House. Vance, who first gained fame as author of the book Hillbilly Elegy about growing up poor in working-class America, has only been in politics for two years. The 39-year-old first-term senator joined the Marines out of high school.