Of all the arguments against Donald Trump, the softest has been his poor prospects for victory in the general election. True, he has consistently polled worse against Hillary Clinton than have Ted Cruz, John Kasich, and virtually every other person who ran. But polls change. And if Trump were to win the Republican nomination, it would be such an earthquake that the political order might be transformed. Clinton, moreover, has huge vulnerabilities. She lacks many basic political skills, and she is a hostage to fortune—in both the usual way, as the heir to an incumbent president, and in the unusual one of being the subject of an FBI investigation.

Yet the electability argument against Trump is hardening, fast. He has a 67 percent unfavorable rating (per the Washington Post/ABC News poll), which would be the highest ever recorded for a major-party nominee, and a net favorable rating of minus-39 among white women and minus-31 among independents. Trump’s numbers aren’t just bad; they’re the stuff of nightmares.