I get the idea of a presidential candidate having a Jekyll-and-Hyde-style split personality. That’s what we always fear, isn’t it? But the strange twist is that in this case, it is the Mr. Hyde half of his personality that Trump is putting on prominent, public display — and the Dr. Jekyll half that he is supposedly hiding away in private. Call it The Strange Case of Dr. Carson and Mr. Trump.

That’s what strikes me as a really significant and ominous development in our political culture. In the original Robert Louis Stevenson version, “The Strange Case of Dr. Jekyll and Mr. Hyde,” Dr. Jekyll is a thoughtful, enlightened, and idealistic scientist who becomes obsessed with the idea that all men have a mixture of good and evil in their souls. He attempts to devise a treatment that will purge the evil part of his soul, but instead he separates it out into an alternate personality. At first this alter ego — the vicious, predatory Mr. Hyde — is small, sickly, and weak, having long been suppressed by the better half of Dr. Jekyll’s soul. But once he is let loose upon the world and has the opportunity to exercise his vicious impulses, he begins to grow larger, more vigorous, and more dominant.

This strikes me as a good metaphor, not just for Trump, but also for what has gone wrong with our political culture. The candidates who built their campaigns around appealing to the better angels of our nature, the ones who were chasing after the Dr. Jekyll vote, didn’t make it this year. And Trump is racking up victories on the strength of the Mr. Hyde vote.

This is a sign that we are becoming accustomed to exercising the negative aspects of our national character.