The deadly mob attack on the U.S. Capitol on January 6, 2021 — exhorted and then cheered on by President Donald J. Trump, with accountability later stonewalled by the Republican Party — was unprecedented in our history, but then again it wasn’t. It is true that never before had a losing presidential candidate, after pounding a Big Lie about a stolen election, helped to whip up a crowd into a murderous frenzy and directed it to prevent the official congressional certification of his defeat. The last time a losing candidate’s campaign tried to overturn the results, in the incomparably closer election of 1960, Richard Nixon’s supporters, having lost by a whisker to John F. Kennedy, tried to raise a stink about massive vote fraud in eleven states. But the Nixon forces gave way, after recounts, judicial decisions, and state board of elections findings — including those under Republican jurisdiction — went against them. Trump, the Roy Cohn protégé who has long regarded Nixon as insufficiently ruthless, pushed much further, to the point of sedition.