Europe demonstrates, however, that socialism and the free market are compatible. The basic issue before the Democratic Party now is how far left to go. Bernie Sanders calls himself a socialist. Kamala Harris calls herself a progressive. John Hickenlooper, conciliator, says he can “get stuff done.”

The notion that American elections are won in the center was buried by Trump. The energy in the Democratic Party lies in the progressive camp. It stems from anger at a skewed economy and millennial disgust at the elitist turn that cost the Democrats their working-class base and much of small-town America. This opened the way for Trump. My own inclinations are centrist, but not a “centrism” that cares more for Goldman Sachs than the opioid crisis. I don’t see how the Democrats can eschew a new era’s left-leaning energy and win.

A word of caution: The United States was founded in contradistinction to, not as an extension of, Europe. Self-reliance is to America what fraternity is to France: part of its core. American space — so immense, so un-European — conjures in Americans a bristling independence of spirit that wants government out of their lives.

Nations do not cast off their cultural essence. I don’t think soaking the rich — Ocasio-Cortez’s proposed 70 percent wealth tax — is going to get a Democrat to the Oval Office. Nor are the accusations of “worker exploitation” that chased Amazon and 25,000 jobs out of New York — a stupid waste.

The dirty secret of European welfare states is that they tend to be business-friendly. As Monica Prasad, a sociology professor at Northwestern University has pointed out, Sweden has a lower corporate tax rate than the United States. The sweet spot for Democrats is getting business to buy in to progressive reform. America can be nudged in a French direction without losing its self-renewing essence.

France is also home to the yellow-vest protests from the marginalized. So much for social cohesion, you might say. But there’s a lesson. As James McAuley observed in The New York Review of Books, those vests reflect, above all, a “material demand to be seen.” Socialism is no silver bullet. The basic requirement of any Democratic candidate is to make the forgotten, the struggling and the invisible of American society feel visible again.