In what has since become known as his first “major” speech, Abraham Lincoln famously warned the Young Men’s Lyceum of Springfield, Illinois in 1838 about the dangers of “mob rule.” As reprehensible as are the immediate consequences of mob rule, however, Lincoln’s larger strategy in the speech is to use our revulsion at the actions of the mob to draw our attention to the long-term dangers of what he calls “the mobocratic spirit.” These dangers move in two directions. In the first place, “the lawless in spirit, are encouraged to become lawless in practice; and having been used to no...