Bernie Sanders always stays on message. If you've heard one of his speeches, you really have heard them all. It's one jeremiad after another about America's long descent into plutocracy. That's his big idea. The rich getting richer and more powerful at the expense of everyone else. In other words, the kind of thing one would expect from a self described "democratic socialist."

What Sanders means exactly by "socialism," however, has evolved over the decades, even if his broader theme of inequality hasn't. Back in the 1970s, Sanders favored the public ownership of utilities, banks, and major industries. But that's not what Sanders supports today. In a 2015 speech at Georgetown University, he defined his version of socialism as to akin Scandinavian-style economic security. "Remember this," he said, "I do not believe government should take over the grocery store down the street, or own the means of production." And when CNN's Chris Cuomo asked Sanders last April about his previous views, he batted away the question: "I was a mayor of a city for eight years. Did I nationalize any of the industry in the city of Burlington, Vermont? I don't think so."

It's okay if politicians and policymakers change their views. Indeed, it would be extraordinarily odd for someone nearing 80-years-old to have been perfectly consistent over the decades. But those changes should be explained. Take Alan Greenspan, for instance. The former Federal Reserve chairman is as much a lifelong supporter of market capitalism as Sanders is a critic. Yet in 2008, Greenspan, then 82, told Congress that the global financial crisis had taught him a harsh lesson. He conceded that he had "made a mistake" in trusting free markets to regulate themselves. "I have found a flaw," Greenspan said. "I don't know how significant or permanent it is. But I have been very distressed by that fact."

What lessons have the events of the last half century taught Bernie Sanders? Are they why Sanders no longer talks about nationalizing industry? He's certainly seen a lot that would seem to have direct bearing on his ideology, especially the collapse of the Soviet Union and the rise of China. Did two of the most significant events of the 20th century give Sanders occasion to question his priors? Was he "very distressed" at the failure of the centrally planned Soviet economy? He certainly should have been, but only offers a condemnation of the authoritarian political system. Despite vast natural resources and a highly educated population, the USSR ended up as a dingy economic basket case. As one 2017 analysis concluded, "During its lifetime, many other countries made similar or greater social and economic gains with more consent and less violence. On its centenary, the Soviet economy should be remembered but not mourned."

Likewise, was Sanders puzzled by how even a bit of economic freedom spurred warp-speed growth in China? It's unclear. Last September, he praised China and its leaders for having "made more progress in addressing extreme poverty than any country in the history of civilization." But those gains didn't come from socialism done right. The economic consensus, as recently summed by the Congressional Research Service, is that it was "foreign trade and investment and implementing free-market reforms" that sparked China's rapid economic ascent.

This all might prove uncomfortable history for Sanders. No wonder he'd rather talk about Scandinavia as his socialist success story. Those tiny economies score well on just about every economic metric. But there's more to them than universal healthcare and generous paid leave. The Nordic model, according to a recent JPMorgan report, "entails a lot of capitalism and pro-business policies, a lot of taxation on middle class spending and wages, minimal reliance on corporate taxation and plenty of co-pays and deductibles in its healthcare system." That's stuff antithetical to the Sanders democratic socialist agenda. Indeed, the report concludes, "A real-life proof of concept for a successful democratic socialist society, like the Lost City of Atlantis, has yet to be found."

Elizabeth Warren calls herself a "capitalist," yet her campaign is a critique of capitalism. Does Sanders have a critique of socialist economics? He has long been a figure of note on the American political scene. Yet voters actually know little about his thinking beyond the simple claims of his repetitive and haranguing stump speeches. Maybe it's about time they found out. Maybe journalists should finally ask.

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