The caucus gyms of first-in-the-nation Iowa transformed Barack Obama from curiosity to contender in 2008. Black-church networks in South Carolina handed Joe Biden the Democratic nomination in 2020. If not for the restaurants and bowling lanes of New Hampshire, Bill Clinton’s campaign and career would likely have been, to borrow a phrase, as dead as the “last dog” in 1992. Picking Democratic presidential nominees in the United States, in other words, has always been a concocted local game . Even