The prospect of a Trump presidency led to some prominent Americans — including Supreme Court Justice Ruth Bader Ginsburg — joking, or perhaps half-joking, that they would move to New Zealand. Ginsburg gave a nod to this splendid isolation during an interview with the New York Times in July. “‘Now it’s time for us to move to New Zealand,’” Ginsburg said her husband would be urging if Trump won the election. Billy Crystal had the same idea. “I might consider finding a nice little ranch in New Zealand,” he told Australian media earlier this year. (By the way, Billy, we...