When the organizers of Occupy Wall Street first gathered to discuss their plan of action, the strategy that resonated most came from those who had occupied squares in Madrid and Athens, Tunis and Cairo. According to David Graeber, one of Occupy Wall Street’s organizers, “they explained that the model that seemed to work was to take something that seemed to be public space, reclaim it, and build up an organization and headquarters around [it].”

Six weeks later, on Sept. 17, the occupation in downtown New York began, with scant attention, minimal and often derisive media coverage, and little expectation that it would light a spark where others had not. Now, in its fourth week, Occupy Wall Street has the quality of an exploding star: It is gathering energy in enormous and potent quantities, and propelling it outward to all corners of the country.

The protesters in the nascent movement have been criticized for being too decentralized and lacking a clear list of demands. But they are bearing witness to the corruption of our politics; if they made demands to those in power, it would suggest those in power could do something about it. This contradicts what is, perhaps, their most compelling point: that our institutions and politicians serve the top 1 percent, not the other 99.

The movement doesn’t need a policy or legislative agenda to send its message. The thrust of what it seeks—fueled both by anger and deep principles—has moral clarity. It wants corporate money out of politics. It wants the widening gap of income inequality to be narrowed substantially. And it wants meaningful solutions to the jobless crisis. In short, it wants a system that works for the 99 percent. Already Occupy Wall Street has sparked a conversation about reforms far more substantial than the stunted debate in Washington. Its energy will supercharge the arduous work other organizations have been doing for years, amplifying their actions as well as their agendas.

Occupy Wall Street is now in more than 800 cities and counting. Each encampment has its own character, from thousands marching in San Francisco to a handful gathering in Boise. These are authentic grassroots operations, so each one will reflect the local culture of protest while reproducing what seems right from the original.

Republicans have reacted bitterly. House Majority Leader Eric Cantor denounced the demonstrators as “mobs,” without noting the irony that when the Tea Party marches, he calls them his most important constituency. Presidential candidate Herman Cain called them “un-American.” Many more on the right have lent their ugly rhetoric to the debate, calling the protests an example of class warfare — as if the ever-widening gap between the 1 percent and everyone else is somehow the product of class harmony. The war has been raging for years, but its victims have been the middle class and the vulnerable, not the rich or the powerful.

The corporate media is waking up to the fact that the Tea Party isn’t the only movement in town; it is, at long last, paying attention to the panoply of progressive left movements across the country. Protesters and marchers under the banner “We are the 99” have been featured on network and cable news and on the front pages of national and regional newspapers. Some in the Democratic Party are also paying attention. The Progressive Caucus endorsed the movement. So did House Minority Leader Nancy Pelosi and progressive champions such as Vermont Sen. Bernie Sanders and former Wisconsin senator Russ Feingold, who said the movement had the power to grow so big and so impactful that it would “make the Tea Party look like a tea party.” Labor has joined in, too, marching alongside protesters at New York’s Foley Square rally last week and in other outposts, trying to drive the street heat energy into the broader political sphere.

Many, if not most of the protesters are openly wary about the embrace of the progressive establishment. Rightly so. The movement, unlike the Tea Party, is not based on electoral strategy, and there is a concern about being co-opted. But I was part of a discussion with key organizers on Sunday showed that most understand that the main task ahead is growing the movement, and that may mean going to where the injustice is — to where people are being evicted from foreclosed homes or losing jobs.

Even so, it’s clear that Occupy Wall Street is already shifting the center of gravity of our public dialogue. Sen. Harry Reid, not exactly known for being a progressive champion, introduced legislation last week that would pay for the president’s jobs bill through a surtax on millionaires. The plan has enjoyed broad support from Democrats in the Senate, not a group usually associated with channeling populist frustration.

President Obama, too, has ramped up his rhetoric, having accepted that reasoning with the unreasonable is a dead end. At an Oct. 6 news conference, the president empathized with protesters, saying they “are giving voice to a more broad-based frustration about how our financial system works.” As always, political leaders move to where the energy is. Now, finally, there is real, concentrated energy on the left.

In the coming days, Occupy Wall Street will face the tests that all fledgling movements do: whether it can sustain its energy, edge and moral compass; sustain its pressure; and, if necessary, evolve on its own terms. Its organizers understand that if the movement succeeds, it can do a great deal to reset the national landscape. It can provide the energy — that spark — to other progressive mobilizations and campaigns that have been toiling to reshape our politics, and keep the flame burning.