Conventional wisdom holds that elections are about the future. Or about the personalities of the candidates. Or at least about voters’ perceptions of the last four years. But a quick glance at history shows that’s not always so. Republicans won every election between 1868 and 1880—not because Ulysses S. Grant, Rutherford B. Hayes, and James Garfield were such fabulous candidates, and not because their Democratic opponents were so awful.