How can a campaign as explicitly revolutionary as Mr. Sanders’s reach voters who already feel exhausted by the dizzying destruction of norms under the Trump administration? It’s simple, I think, or ought to be: The Sanders camp must imagine (to borrow a tongue-in-cheek bit of internet-speak) a “normie” democratic socialist — a person who is in most every sense ordinary but who may still be interested in the benefits of the kinds of programs Mr. Sanders has in mind.

It’s not such a ridiculous idea. In many countries with economic development comparable to that of the United States, the programs Mr. Sanders has built his candidacy on are mundane facts of life: Universal health care, subsidized child care and guaranteed paid parental leave are all de rigueur in much of Europe, for example. This is what led Prime Minister Sanna Marin of Finland to remark that life in her country more closely approximates the American dream than America itself does: “We have a very good education system. We have a good health care and social-welfare system that allows anybody to become anything.” In other words, the way of life sought by recipients of the kinds of programs Mr. Sanders proposes isn’t radically different from the way of life many, if not most, Americans aspire to. It’s just easier to actually live it there.