In May 2012, at the height of the Occupy Wall Street demonstrations, the journalist Sarah Jaffe took a walk through New York City. Stopping by The New York Times building, she witnessed a protest unfold there; blocks away at Bryant Park, other demonstrators had gathered. As she walked to lower Manhattan, she encountered several more. “And I thought, ‘OK, something’s happening here,’” Jaffe says.

It wasn’t just Occupy Wall Street—Jaffe recognized the energy of unrest that had been bubbling over in the United States since the 2008 financial crisis and spread into the movement for black lives, the fight for fair wages, and clashes over environmental policies. Jaffe united these movements in a book, Necessary Trouble: Americans in Revolt, which came out this past summer.

In November, after Donald Trump was elected President of the United States, Jaffe almost wished she had waited. As protests ignited in cities across the country and the gears turned on plans for mass demonstrations surrounding the inauguration, Jaffe identified the same undercurrents of discontent that had activated the movements she spent years immersed in.

CityLab recently spoke with Jaffe about why cities will be the places demonstrations take root.

You’ve had your finger on the pulse of protests and movements in the U.S. since 2008. What have you learned about what makes a demonstration powerful?

The thing that the movements since 2008 have done, with varying degrees of “success,” is not just counted on a mass march to make a statement, but really tried to be disruptive in new ways. The Tea Party—which was a disruptive grassroots movement in its own right—managed to push Republicans to do what they wanted to do, which was obstruct anything Obama wanted to do. And Occupy Wall Street was powerful because it was different from what we expected. Those demonstrations weren’t just a march—if Occupy had walked through Wall Street on a Saturday and then gone home, nobody would’ve cared. But it was the fact that they stayed—which can be said of the Standing Rock protest, too—that really made people pay attention.

It seems like new uses of public space are also a factor in the way demonstrations are striving for power today. The labor protest in Madison saw people sleeping on benches outside government buildings, and the Occupy movement configured itself around taking over plots of city land. What is the significance of this?

In terms of holding space in cities, the powerful thing about Occupy is that even though you might be in, say, New York City, and you run into a million people on the street each day, you don’t really communicate with them. The Occupy demonstration was a space that people could actually talk to each other and were expected to talk with each other.

The Fight for 15 movement started in New York City because there’s something like five fast food restaurants in every two blocks, and it was very easy to bring all of these people together. That comes from David Harvey’s book, Rebel Cities: the idea that in urban areas, you have these spaces where you can incubate resistance and incubate policy ideas. You see minimum wage increases going city by city, starting in Seattle and going from there. We see paid sick days starting in cities. These things show you what you can actually do.

What will be the most effective course of action for people organizing and demonstrating in the coming years?

A lot of this work will come out of cities. Most big city mayors are Democrats, and if you want to make progress on issues like policing and immigration, those are the first levers to push.

You know, a million people can march on Washington, and [Donald Trump] is just going to laugh and still be president. But what movements can do is engage people, and bring them out to answer the real question going forward, which will be: What do people need? What are they not getting from existing politicians? Then if we actually plan and demand things out of city governments, and look forward to solutions that can be implemented two years from now, then four years from now, that will be a real source of power.