Absurd as it was, though, Mr. Stein’s remark was not all that far removed from mainstream American public opinion. Even the liberal “left” in this country is densely populated with politicians whose stated views on socialism seem scarcely more exact.

It may be amusing to hear Republicans assert that a military kleptocracy like Venezuela is a socialist country because its government uses that word when lying about itself (rather in the way that North Korea claims to be a people’s democratic republic). It may make one wince to see Senator Bernie Sanders obliged (as he was on Monday at a town hall hosted by CNN) to explain once more that the totalitarian statism of the Soviet Union had nothing to do with the (far older) tradition of democratic socialist thought. But fair’s fair, it’s not much less bizarre to hear a “progressive” like Julián Castro, the former housing secretary, assert that “socialism” simply means state seizure of all the means of production. (Had Marx and Engels only known this, they might have spared themselves the effort of denouncing the socialists of their time for failing to call for a completely centralized economy.)

Well — only in America, as they say. Only here is the word “socialism” freighted with so much perceived menace. I take this to be a symptom of our unique national genius for stupidity. In every other free society with a functioning market economy, socialism is an ordinary, rather general term for sane and compassionate governance of the public purse for the purpose of promoting general welfare and a more widespread share in national prosperity.

In countries where, since World War II, the principles of democratic socialism have shaped public policy (basically, everywhere in the developed world except here), the lives of the vast majority of citizens, most especially in regard to affordable health care, have improved enormously. This is acknowledged by almost every political faction, whether “liberal” (like Social Democrats), “conservative” (like Christian Democrats) or “progressive” (like Greens). And the preposterous cost projections that American conservative propagandists routinely adduce to prove that “socialized medicine” or a decent public option would exhaust our Treasury are given the lie in each of those countries every day.

Democratic socialism is, briefly put, a noble tradition of civic conscientiousness that was historically — to a far greater degree than either its champions or detractors today often care to acknowledge — grounded in deep Christian convictions. I, for instance, am a proud son of the European Christian socialist tradition, especially in its rich British variant, as exemplified by F.D. Maurice, John Ruskin, William Morris, R.H. Tawney and many other luminaries (including, in his judiciously remote way, C.S. Lewis), but also in its continental expressions (see, for example, Pope Pius XI’s encyclical Quadragesimo Anno, with its prescient warnings against the dangers of unfettered capitalism).