... I like Sanders. I love that he’s hammering home this lesson— that populism is popular—to frightened Democratic elites. I’m gobsmacked that in a mere matter of weeks, he has upended a generation’s cobweb-encrusted psephological clichés. What’s more, I distrust Hillary Clinton, and I fear the message that would be sent to those selfsame Democratic elites by the success of a candidate for whom four of the five top contributors to the $712.4 million she’s raised for her campaigns since 2000 were banks.

I just fear what will happen if Sanders becomes president: precisely because he’s proving the economic populism argument right.

I made a detailed argument about the power of economic populism to strengthen the Democratic Party in an essay in the Boston Review in 2004, later published with responses in a book called The Stock Ticker and the Superjumbo: How the Democrats Can Once Again Become America’s Dominant Political Party. I compared political parties to corporations. The most successful ones, historically—the great ones—built long-term value by developing a reputation for innovative, quality products. More and more, however, beginning with the rise of the modern “go-go” stock market in the 1960s, companies began the practice of impressing short-term investors by measuring success in quarterly increments, via expediencies like selling off slow-moving divisions, liquidating excess capacity, and trimming research and development. David Halberstam explained in The Reckoning, his classic history of the auto industry, how the Big Three Detroit automakers destroyed themselves in precisely this way.

After the traumas of the Reagan years, that was how the Democrats began to go about things, too: they grabbed desperately at whatever initiative—or abandoned whatever initiative—they felt it would take to nose enough “swing voters” temporarily into their column to garner 50 percent plus one in the next election. But a swing voter is like a short-term shareholder—ready to sell the next time some other blandishment comes along.

As the alternative, think of the Democrats who created Social Security in 1935—it is still delivering loyalty to Democrats 80 years later. As is Medicare, which was passed in 1965. If it fulfills its promise, Obamacare might still be manufacturing Democrats decades hence.

I called such programs “superjumbos.” But one characteristic of a superjumbo is that a president doesn’t just order one out of a catalogue. They are almost by definition long in gestation. Much of the great social legislation of the New Deal was conceived in the Progressive Era. All the extraordinary string of laws Lyndon Johnson passed in the first two years of his presidency, like the first bill providing federal aid to education, and Medicare and Medicaid, had been in the hopper for a generation or more—even back to Theodore Roosevelt.

The Great Society’s progressive momentum was abruptly halted by the backlash against civil rights, a story I told in my book Nixonland. But I also missed something in Nixonland—the superjumbos kept coming, only in different form. Starting in 1966 with the National Traffic and Motor Vehicle Safety Act (its seat-belt requirements save 10,000 lives a year), the Federal Hazardous Substances Act, the Federal Meat Inspection Act, the Truth in Lending Act, and continuing through the Nixon presidency with the Federal Coal Mine Health and Safety Act, the Occupational Safety and Health Act, and the National Environmental Protection Act, Democrats wrote an entire new story in America’s books of law: that the federal government could act aggressively to protect consumers from corporate malfeasance.

“Consumer legislation” was an entirely new category of statute—but, just like the New Deal and Great Society social legislation, political entrepreneurs, both inside Congress and in the advocacy community, had been working to advance it for years, in faith that their moment would come. In May 1969, for example, only 1 percent of those polled considered “pollution/ecology as an important national problem,” according to University of California, Berkeley, professor David Vogel’s Fluctuating Fortunes. But by December 1970, a survey revealed that the same problem ranked number one in the public’s concern. Senators like Gaylord Nelson of Wisconsin and Maine’s Edmund Muskie were ready to act; meanwhile, President Nixon, helpless before the power of public opinion, had no political choice but to go along.

To me, this history reveals the frustrating paradox at the heart of Sanders’s success. The very thing that makes it so exciting—a Democrat dreaming big dreams and who’s rewarded with burgeoning political success beyond anyone’s prediction but his own—is also what makes for such a stark contrast with the rest of the Democratic Party. The fact is that Sanders is nearly alone. In our generation, the dreamers have been the conservatives in the Republican Party. As one of them, Milton Friedman, put it in a quote made famous by Naomi Klein’s The Shock Doctrine, in a crisis, “the actions that are taken depend on the ideas that are lying around. That, I believe, is our basic function: to develop alternatives to existing policies, to keep them alive and available until the politically impossible becomes the politically inevitable.” ...