Self-described socialist Bernie Sanders has become a favorite of young voters by posing as an apostle of daring new ideas. Socialism, however, is anything but new. It’s hard to think of another idea that has been tried and failed as many times in as many ways or at a steeper price in human suffering.

The term “socialism” was coined by followers of Robert Owen (1771-1858), whom Karl Marx would label a “utopian socialist.” In 1825 Owen founded New Harmony, an Indiana commune, to demonstrate the superiority of what was first called the “social system.” The same year, Owen explained his experiment to a joint session of Congress attended by Supreme Court justices, President James Monroe and President-elect John Quincy Adams. Although Owen poured his fortune into it, New Harmony collapsed in disarray and recrimination within two years.

Owen’s son Robert Dale Owen salvaged the community by implementing what he called “a policy the very reverse” of socialism: “giving each respectable citizen every facility and encouragement to become (what every adult ought to be) a landed proprietor.”

Undeterred, others founded some 40 to 50 similar communes during the 19th century, and all collapsed quickly. New Harmony’s two years proved to be their median lifespan.

Based on the uniformly dismal results, the idea of socialism might have died a quiet death were it not for Marx (1818-83), who transformed socialism from an experiment—tried, tested and failed—into a prophecy, “the riddle of history solved.” Ironically, he called his vision “scientific socialism.”

Inspired by the dream of proletarian revolution overthrowing capitalist immiseration, socialist parties sprouted across Europe. Yet instead of growing poorer, workers in industrialized countries saw improvement in their living standards; and instead of disappearing, middle classes expanded—all disproving Marx.

It took Vladimir Lenin’s “vanguard” and the horrors of World War I to give socialism new life. In Russia, Lenin pioneered modern communism, which in the 20th century was imposed on 18 countries and one-third of mankind. Repression was justified by socialism’s purported economic benefits, but the actual trade-off entailed economic misery and the snuffing out of as many as 100 million lives.

Today Communist parties rule six countries. Most follow the lead of China, where the party redefined itself to include entrepreneurs. A 2012 Wall Street Journal report identified 160 people with an average net worth of more than $1 billion holding high government or party seats. No Chinese Bernie Sanders rails against them.

“Social democrats” and “democratic socialists” rejected Lenin’s methods. But their goals remained transformational. As British Labour Party leader Clement Attlee, who became prime minister in 1945, explained: “Our policy was not a reformed capitalism but progress toward a democratic socialism.” Labour sought to bring “main factors in the economic system”—including banks, mining and energy—under “public ownership and control.” Nationalization worked so badly, however, that Attlee soon beat a retreat and was voted out in 1951.

In 1981 Socialist François Mitterrand was elected president of France promising a clean “rupture” with capitalism. The results of his spending and nationalizations were so alarming that in 1982 Mitterrand reversed course and implemented austerity measures, which he dubbed “socialist rigor” to save face. “The aim is to bring about a real reconciliation between the left and the economy,” explained Socialist Party chief Lionel Jospin.

American socialists like Mr. Sanders, while often defending the likes of Fidel Castro, Daniel Ortega, Hugo Chávez and Nicolás Maduro, prefer to point to Scandinavia as a model. But Scandinavian social democrats learned to settle for dense social safety nets underwritten by remarkably free, capitalist economies. On the World Bank’s Ease of Doing Business scale, Denmark ranks third of 190 countries, Norway seventh and Sweden 12th.

Read the full article in The Wall Street Journal.