The capital’s schism spotters, shifting their attention away, for the moment, from the G.O.P., have begun looking leftward—which is the direction in which they see the Democrats moving. The Party, according to the Washington Post, is debating its shape, post-Obama, and the populists are winning. The Post—and it is hardly alone in this view—sees a widening split, both “stylistic [and] substantive,” between “the establishment and a newly energized populist wing,” led by Senator Elizabeth Warren and Mayor Bill de Blasio. (The next time Rush Limbaugh says that Democrats want the rest of the country to be just like Cambridge, Massachusetts, or New York City, it’s going to be harder to argue with him.)

Populism, at present, is less a platform than a gestalt. It boils down to a few basic inclinations: to have the rich pay more in taxes, to have the government provide more in services, to decry inequality of income and opportunity, and to get tougher (preferably a lot tougher) on Wall Street and mollycoddled corporations. And, not least, to feel perfectly comfortable saying all of the above.

This is stronger stuff, certainly, than Democratic politicians have offered in a quarter century or more, and reveals a slackening—if not quite a release—of the centrist hold on the Democratic imagination. Since 2011, at least, President Obama has sounded these themes consistently, and, as reports Friday revealed, the Administration’s budget request for 2015 calls, without apology, for an increase in spending on programs to benefit the middle class.

But the power and the appeal of populism are in the process of being wildly overstated by both the right and the left, each for its own purpose: the right, to instigate a Democratic civil war, and the left, to win one. Activists like Adam Green, a founder of the Progressive Change Campaign Committee, say that the populists not only are doing “battle” with “the corporate wing of the Party,” they are prevailing. Markos Moulitsas, the founding syllable of Daily Kos, has told The Atlantic that, “on everything from economic populism to marriage equality to gun control,” the Democratic Party has moved to the left.

There is a good deal of truth to Moulitsas’s view. Still, 2014 is likely to be a frustrating year for the Party’s populists. The Democratic Senatorial Campaign Committee, for good reason, is far less concerned with creating more Warrens than with saving the Landrieus and Pryors and Hagans it’s already got—red-state senators who are running for reëlection and away from the President, the Affordable Care Act, and anything that smacks of old-school, large-scale federal intervention in the economy. Organized labor will keep up the fight for economic justice—“raising wages for all workers is the issue of our time,” Richard Trumka, the president of the A.F.L.-C.I.O, said this week—but with these Democratic senators under electoral duress, putting the Party’s control of the chamber in jeopardy, a more full-throated liberalism is likely, for the time being, to be leashed, even muzzled.

This cannot augur well for the new populism. Looking beyond this election cycle, there is little reason to expect the populist moment to endure—or to transform, to any substantial degree, the Democratic Party. Absent a cataclysmic event—say, another economic collapse—Democrats are likely to remain stubbornly middle-of-the-road in temperament and in their agenda; odds are against a sharp leftward turn that mirrors the sharp rightward turn that the G.O.P. has taken. There are at least two reasons for this, the first being that Democrats have learned something from past elections, principally that the farther out you venture (or are seen to venture) toward the ideological margins the more likely you are to lose.

This would seem a truism if the Republican Party weren’t so blind to it. One could call it the Cruz fallacy, although Senator Ted Cruz is only one of a seemingly endless chain of conservative politicians and commentators who have said something like the following: “If you look at the last forty years, a consistent pattern emerges. Anytime Republicans nominate a candidate for President who runs as a strong conservative, we win. And when we nominate a moderate … we lose.” Extremism, happily enough, really is no vice electorally; the key to victory is ideological purity.

This is a typical misreading of the 1980 election—the idea that Reagan won the White House not because of the state of the U.S. economy or events in the Middle East or the sad ineptitude of Jimmy Carter but mainly because he offered voters an undiluted conservatism. It is also the founding myth of modern Republicanism, so there’s no sense in trying to talk them out of it. Hence the lament, every time the Republicans do lose, that the Party should have put forward a “real conservative,” instead of Ford/Bush/Dole/McCain/Romney, milquetoasts all. As hard as it is to imagine Mike Huckabee performing better than John McCain did in the fall of 2008, or Rick Santorum posing more of a challenge to Obama, in 2012, than Mitt Romney did, this remains, for many Republicans, an article of faith.

Of course, there are Democrats who believe that a “left turn” is the way to win elections in a “rout.” This can be called the Westen fallacy, after Drew Westen, a psychologist and sometime strategic consultant, who has been making this case in the Times and elsewhere. Yet few Democrats are hitting the turn signal. Almost across the board, moderation prevails. It is not only corporate contributions, as Westen and other progressives darkly suggest, that bind Democrats closely to the political center and inure them to class-based appeals. It is the Party’s institutional memory of being tagged—successfully—as something alien, an affront to middle-class culture and values. If four-letter words like “A.C.L.U.” don’t pack the punch that they once did, it’s because leading Democrats, for a generation now, have steadily refused to fit the old caricature. This takes vigilance. Governor Jack Markell, of Delaware, recently warned his fellow-Democrats never to forget “where the people of the country are,” unless they want to repeat the electoral debacles of 1972 and 1984.

There’s another, perhaps deeper, reason for this. Even in their heart of hearts, even where the ideological id runs free, most Democrats do not thrill to the populist mantra of higher taxes and bigger government. Reforms such as universal pre-kindergarten and an increase in the minimum wage are broadly popular—and the Party, locally and nationally, is pursuing them. And there is great, if largely untapped, enthusiasm for the populist crusade to reduce the role of money in politics. But, on the whole, Democrats’ eagerness for, and confidence in, governmental action is thin and equivocal. According to the Pew Research Center, the share of Democrats who think “it’s the government’s responsibility to take care of people who can’t take care of themselves” is no higher today than it was twenty-five years ago. (Meanwhile, Republican support for that idea has plummeted.) A Gallup poll last December showed that a majority of Democrats, fifty-six per cent, view “big government” as a greater threat to the nation’s future than “big business”—a number that must, to some extent, reflect concerns about government eavesdropping, but is also consistent with polls taken well before the Snowden revelations about the N.S.A. The decades-long societal slide of our faith in government continues—not without interruption, but without real hope for a reversal. In this sense, the chief obstacle to a populist future might be the populist agenda itself.

That’s why, even as they advocate new and expanded federal programs, populists would do well to develop a platform that does not rest, in most instances, on the appropriations process. So much of the real action is elsewhere now, outside the nation’s capital, a lot of it in the private sector—a source of creative, disruptive energy that progressives ought not to reject reflexively but to harness, where possible, to the social aims that they seek. This would not constitute stale split-the-difference liberalism; it would be pragmatism, of an improvisational, even enlightened sort, and might just help Democrats realize their ideals.

So go ahead and call centrism soulless, craven, corporatist, or anything you like. But, during recent decades, Democrats have found the political middle ground to be vast and bountiful. That territory has also been increasingly abandoned by Republicans, who tend to cluster on the edge of cliffs. Why would Democrats want to join them there?

Jeff Shesol, a former speechwriter for President Clinton, is the author of “Supreme Power: Franklin Roosevelt vs. the Supreme Court” and is a partner at West Wing Writers. Follow him on Twitter at__@JeffShesol.

Photograph by Andrew Harrer-Pool/Getty.