In “Chasing Hillary: Ten Years, Two Presidential Campaigns, and One Intact Glass Ceiling,” reporter Amy Chozick confirms this was no one-off gaffe. Mrs. Clinton, she reports, used the line repeatedly to Democratic audiences she knew would appreciate the sentiment.

“The Deplorables always got a laugh, over living-room chats in the Hamptons, at dinner parties under the stars on Martha’s Vineyard, over passed hors d’oeuvres in Beverly Hills, and during sunset cocktails in Silicon Valley,” wrote Ms. Chozick. The unspoken corollary is that only a morally debased citizenry could have freely chosen Mr. Trump over Mrs. Clinton.

Today few publicly call Trump voters “deplorable.” But the assumption remains. Remember that high-school kid from Covington, Ky., who was accosted by a Native American activist? Simply because he was wearing a “Make America Great Again” hat, the 16-year-old was instantly transformed into the face of white supremacy by a good part of the American media.