On Dec. 1, 1960, the far-right preacher and racist demagogue Gerald L.K. Smith sent out a fund-raising appeal, headlined with a shocking claim in red type across the top: “HOLD YOUR BREATH: KENNEDY MAY HAVE LOST.” The 1960 election had indeed been close, but the Democrat, John F. Kennedy, had prevailed, and his Republican opponent, Richard M. Nixon, had congratulated Kennedy on election night, over shouted protests from his supporters. Three weeks later, Smith, the leader of what he...