Hillary Clinton’s comment that half of Donald Trump’s supporters are “racist, sexist, homophobic, xenophobic, Islamophobic”—a heck of a lot of phobia for anyone to lug around all day—puts back in play what will be seen as one of the 2016 campaign’s defining forces: the revolt of the politically incorrect.

They may not live at the level of Victor Hugo’s “Les Misérables,” but it was only a matter of time before les déplorables—our own writhing mass of unheard Americans—rebelled against the intellectual elites’ ancien régime...