Trapped in the fog of conscientious obscurantism, Twitter-wracked neurosis, blatant bungling, executive-order malfeasance, lurking corruption, lifeboat ethics, and neo-fascist quasi-ideology, we may well want to look for clues to the interior life of the Social Darwinist thug presently making a landfill fire of the federal government. The red-alert tenor of the moment is unprecedented, and as the despair grows with each passing week, any clue will do, because while we know too much about Donald Trump, we also know almost nothing. Glimpses inside, as chilling as that sounds, have been rare. Amid the scant psychobiographical residue, there’s one simple stated fact that continues to bedevil me: that Trump has gone on record, more than once, as saying his favorite film of all time is Orson Welles’ Citizen Kane (1941).

As with many cultural indices (chocolate vs. vanilla, what sort of self-aggrandizing tattoos you have, who’s your favorite Monkee), favorite films can be revealing—of one’s weaknesses and delusions, more often than not. But rarely has the juxtaposition between a public figure and his or her most treasured classic film been more confounding, and filthier with contradictions. (George W. Bush cited Field of Dreams as his fave, a daydreamy choice that wouldn’t even surprise the population of Iraq.) At first blush, Trump’s choice of Citizen Kane suggests two contradictory things: that Trump may in fact have far better taste in movies than we might ever have guessed, and that he doesn’t understand the Welles film at all. It is unarguably something like Pat Roberts proclaiming his allegiance to Elmer Gantry. But of course it is more complicated than that.

A throng of commentators made click-bait hay late last year about how Trump must’ve missed the point of Citizen Kane, a collective yowl of irrelevance that in itself misses any chance of understanding either Citizen Kane and Trump’s ardor for it. Kane is about as far from being a didactic work, with a “point,” as any film made in America; in its dogged ambivalence it invites interpretations but resists conclusions. Just as in its plot’s famous narrative gambit—the newsreel reporter’s search for the meaning of the billionaire-deathbed last word “Rosebud”—the movie, through its characters, offers multiple guesses and suppositions and ideas, while at the same time readily admitting their inadequacies. The burning sled with its “Rosebud” insignia melting off at the film’s end plants what seems to be a decisive answer—but it depends on exactly how we read its significance in Kane’s mind as he dies, a consciousness that we are never privy to, in a first-person sense, for a single moment during the film’s overlapping-pancake, questionable-witness accumulation of story. Did he bereave his childhood, or his mother in particular, or himself as...