Republicans, preoccupied with their Tea Party zealots, mostly have avoided joining the debate, but the Wall Street wing of the Democratic Party raised the alarm. In an incoherent article appropriately placed in the Wall Street Journal, the New Democrats at the Third Way scorned Warren for defending Social Security and Medicare and peddling a “dead end” “we can have it all fantasy.” They beat a hasty retreat when they were slapped down by Neera Tanden, head of the Obama New Dem Center for American Progress, who then labored to paint Bill Clinton – Bill Clinton – as a populist. Gaseous Bill Keller of the New York Times weighed in for what he called the “center-left” against the “left-left” of Warren et al with arguments immediately dismembered by economist Dean Baker.

The Beltway crowd has discovered populism. Senator Elizabeth Warren’s surging popularity from her aggressive defense of Social Security and demand for Wall Street accountability has triggered talk of a populist challenge to Hillary Clinton in 2016. Bill De Blasio indicted New York’s gilded age inequality in his stunning victory in the New York Mayoral race. This month, President Obama returned to his campaign themes, delivering a speech calling inequality “the defining challenge of our time.”

These are but the opening skirmishes of what is likely to be a fierce battle inside and outside the Democratic Party. Populism, by definition, doesn’t trickle down from the top. It spreads as a bottom up movement that chooses and elevates its own leaders. It doesn’t spread because Elizabeth Warren is espousing politically toxic and unpopular ideas, as the Third Wayers charged. Rather Warren is threatening because she champions attitudes and ideas that enjoy widespread popularity outside the beltway, but are slighted inside of it.

Populist movements grow out of popular discontent. For over thirty years, inequality has been growing. Profits and productivity and CEO salaries have risen, but workers haven’t shared in the growth. But hard times, as Lawrence Goodwyn, the great historian of the Populist Movement notes, do not generate democratic movements. Times have been “hard” for most people for a long time. When families lose ground, people tend to believe that they are at fault, that their luck has been bad, that they made the wrong choices. They work harder; they take on debt; they get by. Resignation and deference are normal. Movements start only when reality – and organizers – begin to open people’s eyes.

The economy hasn’t worked for working people for a long time. Wall Street’s excesses then led to the Great Recession. Yet the banks were bailed out; banker bonuses were paid, while homeowners were abandoned. The wealthy recovered, while most Americans struggle to stay afloat. Occupy Wall Street helped crystallize people’s sense about the 1%. They rig the rules, as Elizabeth Warren put it, to benefit themselves. Running for re-election in a lousy economy, the president was wise enough to embrace populist themes. And Mitt Romney, with his money summering in Cayman Island tax havens, proved the perfect foil.

This emerging awareness seems spreading among millennials, who, as Peter Beinert detailed, are entering the worst jobs market since the Great Depression. It also finds fertile grounds among people of color and single women, hardest hit in the recession and having a hard time recovering from it. That is the threat: Obama’s ascendant “rising American majority” is looking for change and open to populist arguments.

Sen. Elizabeth Warren, actively involved with the on-line activists who helped propel her candidacy (and raise her tons of dough in small contributions) gets this. So does Sen. Sherrod Brown who won election in Ohio with a populist indictment of our trade policies, and Sens. Sheldon Whitehouse, Tammy Baldwin, Jeff Merkley and, of course, Bernie Sanders. They are in the lead because they understand not only the morality of the populist argument, but its political appeal as well.

Keller suggests that the populists are for redistribution while the “center-left” New Dems focus on growth, but this is a burlesque. The populists are looking for economic growth that works for working people. They opposed austerity policies that gave reducing budget deficits priority over putting people to work. They champion investments vital to our future – in everything from rebuilding our decrepit infrastructure to capturing the lead in the green industrial revolution to investing in education. The Congressional Progressive Caucus budget showed how we could afford those investments and put people to work, paying for it with progressive tax reforms. And they offer answers at the scale of the challenges we face, not the symbolic gestures favored by New Dems as political message.

Similarly, the populists are for predistribution, not just redistribution. With the top 1% pocketing fully 95% of the income growth of the society, populists want workers to be able to capture a fair share of the profits and productivity they help to produce. So they champion not just increasing the minimum wage, but empowering workers at the workplace to organize and bargain collectively. And they will push to curb perverse CEO compensation schemes that give executives multi-million dollar personal incentives to loot their own companies.

The new populists understand that entrenched interests fix the game and feed off the public trough. They want to get health care costs under control not by cutting Medicare, but by taking on the drug and insurance companies and hospital complexes that make our health care costs twice those of other industrial countries. They want an end to subsidies for Big Oil. They would end the tax breaks enjoyed by multinationals that ship jobs or report profits abroad. They would insure that billionaires pay higher taxes than their secretaries. And then use that money to pay for good public education for all children, to make college affordable, to be serious about advanced training for workers.

This debate isn’t simply, as Neera Tanden implies, about championing a small tax hike on the rich to pay for universal preschool and other good programs. We’re about to have a brutal debate about trade policies when the president seeks “fast track” trade authority to push through treaties being negotiated in secret with multinationals at the table and workers locked out. Populists want an end to the corporate defined trade policies that have racked up record deficits and devastated American manufacturing. They will challenge Wall Street’s “strong dollar” policy that benefits investment abroad but makes things made in America less competitive.

And we’ve only begun, as Elizabeth Warren illustrates, the debate about Wall Street. Populists will demand the breakup of the big banks, and curbs on the casino economy.

Will the populist movement spread? That, of course, remains to be seen. Historically, this requires not simply bad times, discontented people and articulate leaders, but grassroots educators and organizing, teachers that challenge the conventional wisdom and give people a chance to see the world anew. In the original populist movement at the turn of the 19th century, this involved literally tens of thousands of itinerant lecturers, speaking in barnyards and town squares, educating gatherings of farmers and workers, enlisting them in an independent organization that provided real service. Today, it involves everything from Occupy’s teach-ins to the space provided by the new media to the organizing initiatives driven by unions and increasingly ideological grassroots organizations.

If the populist movement spreads, it won’t be a Beltway phenomenon. As Occupy demonstrated, it will disrupt business as usual. It will feature fierce battles over basic issues and corruption. Democrats will have to decide how to respond. However disruptive, this is democracy’s promise: That there is space for fiercely independent citizen movements to take on very powerful interests, to challenge Gilded Age inequalities and deep-pocket money politics, and make the economy work for working people once more.