Half a million people were estimated to have attended Saturday’s Women’s March on Washington. More than 600 sister events were held around the world. The outpouring of activism generated national media attention.

But the true test of the demonstrations wasn’t on Saturday. Instead, the key will be if their energy and passion can be channeled into organizations built for a longer fight — and whether those institutions will effectively defend the march’s agenda in the months and years ahead.

“What will they do after the march? How are we going to harness all of these people marching to actually change things?” says Becky Bond, co-author of a new book on organizing with Zack Exley called Rules for Revolutionaries: How Big Organizing Can Change Everything.

Bond adds, “We have step one: massive numbers of people raising their hands. The question is if there will be an organizing group that can take that and use it to change things, rather than have this be an expression of anger and discontent alone.”

Bond and Exley are veterans of the Bernie Sanders campaign, and helped build the volunteer juggernaut that defied the odds and almost defeated Hillary Clinton last summer. In the wake of Donald Trump’s win, they now say the work of mass organizing is more important than ever.

Last week, we discussed the mechanics of community organizing, who should do it and why, and how they think of its usefulness for those who want to slow Trump’s agenda. A transcript of our conversation follows, edited for length and clarity.

What is community organizing?

Jeff Stein

So President Obama comes out in his farewell address, and his main recommendation for fighting the new president — who he characterized as an existential threat to the country — was to go lace up your shoes and “community organize.”

I think a lot of people hear that and don’t really know what it means or how to do it. What is the big-picture idea of community organizing? And in real concrete terms, how can it make a difference?

Becky Bond

Community organizing is literally when members of the community come together and set their own goals for what needs to happen. Then they figure out how to use the resources they have to make the change they want to see.

So how do we get from the world as it is to the world with the goals we set out for ourselves? When you look at members of the community, you start by looking at the resources they have — it’s not typically a big pile of money sitting around.

It tends to instead be people willing to volunteer their time and work to make something happen. So community organizing is built around tactics that take advantage of those resources — like going door to door and talking to people, and building a large number of people to demand change. People tend to have the most impact by going to their elected officials as voters to demand a change, or going to a corporation as consumers to demand change.

But step one is to get enough people working toward the change to get whatever obstacle they identify overturned, and then trying to build the power with the resources they have at hand.

Jeff Stein

What are the levers of power community organizers try to use? Walk me through what a community organizer can build.

Becky Bond

It can’t just be a list of people who support a cause, though that’s often the first building block. That’s where you see these groups today doing these massive petitions, to demonstrate and identify people who support a certain cause.

But then step two is that you need the people who raised their hand and said they support a cause to actually do something on behalf of that cause — because the politicians and decision-makers are often willing to go against what the majority wants if they feel like there will be no repercussions.

So that can be anything from what the Tea Party did in 2009, which was going to town halls with their pitchforks and scaring elected representatives into believing they’d be voted out of office if they weren’t responsive to them. Or it can be to actually running primary races against the candidates who vote against the interests of those people.

Mass demonstrations are certainly important to this. We’ve also seen things like when people shut down the internet over the [Stop Online Piracy Act] fight and sites started to go black — that kind of thing starts to get the message across.

And there’s massive phone calls to representatives, which is what happened when Republicans tried shutting down the ethics watchdog. All of these things, depending on what their scale is, can have a direct effect on elected officials.

Jeff Stein

You’re talking about these mechanisms of power you’re tying to use, and my understanding is community organizing is creating the infrastructure to do those things. What does that look like? Does it have to be around a movement or a cause?

Becky Bond

That infrastructure takes different forms. But at its base, it is a group of people that meet together and take action together. What we see most commonly — and we’ve seen the need to refine this a bit — but it’s the Saul Alinsky model of a “mass power organization.”

That’s where you have a paid and well-trained organizer who goes into a community and organizes people into what Alinsky called a mass power organization. The point of building this is to harness the people to have disruptive demonstrations, to show up at meetings, and to actually sow power — so the organizer could then go to a negotiating table and exact small wins with the power brokers. These are literal membership organizations that people align themselves with, so the organizer can then go into negotiations with lawmakers or a company or whoever, and say, “Here is what the members of this organization stand for.”

But there’s lots of forms of community organizing that happen all the time that don’t fit this model. Right now we’re seeing these massive women’s marches — there’s more than 600 of them happening around the world, started by people who had the same idea: wanting to march with other women to protest the inauguration. That’s a formal organization that’s come together mostly through social media and has gotten bigger through meetings in person, and people have come together with different ideas.

You also have these affinity groups coming together for planning civil disobedience. And a group of people allied together to create resistance events. These are less centrally organized.

What you have with the Women’s March is that massive numbers of people are going to participate — but what will they do after the march? How are we going to harness all of these people marching to actually change things?

That’s the challenge of organizing: We have organizations as we know them, like nonprofits, that can’t organize at this scale — they’re too worried about insurance; they’re worried about brands; they can’t get enough people. Then you have all of these people organized around an idea — but how do you actually translate that into an agenda and a campaign?

What I think we’ll need to see is what we call an ask. All of these people will come together, but what can they do to actually change things? Hopefully, smart state or local groups will swim in that stream to recruit people for longer-term efforts to change things.

The good news is we have step one: Massive numbers of people raising their hands. The question is if there will be an organizing group that can take that and use it to change things, rather than have this be an expression of anger and discontent alone.

What to do if you want to be a community organizer

Jeff Stein

So let’s say there’s a 24-year-old in Iowa who hears Obama’s call to organize and wants to help. What do you tell that person to do?

Becky Bond

I have two answers to that — one specific, and one general.

The general answer is that if people see a group or person with a strategy they support, they should join it. If they don’t, they should call together in-person meetings of people who feel as they do and come up with a goal — whether it’s in Iowa trying to defeat people like Steve King or creating a sanctuary cities movement to protect immigrants there from arrest. There’s lots of things in your community where they’ll have a role in the opposition and the resistance. But it all starts with like-minded people getting together.

I’ve had people who have been telling me, “I’ve been asked to march, but I haven’t been asked to actually do something after it.” My advice to them is: “Well, take a clipboard to the march; there will be lots of people who feel the same way. Then get their names and numbers and start meeting.”

Volunteers from the Bernie campaign are working on something to test at the Women’s March — it’s called “Knock Every Door.”

The idea is to get everyone who came to march to start doing door-to-door canvassing, going door to door in their communities to knock on every door — not just on the list the Democrats have — to find out whether people voted; if so, who they voted for; and what they’re looking for in the next election. And really trying to create this feedback loop with a focus on the counties that flipped from Obama in 2012 to Trump in 2016.

The idea is to both understand what happened there and start that channel of conversation that we think is missing. And to put in place this building block of organizing — talking to people, finding who is with us, finding who needs to be persuaded, and starting the hard work of building a majority for the fights to come.

This is really hard work. We need the camaraderie. Resist the way the system is set up to act individually, by either giving a donation or signing a petition. Do those things, sure. But you also have to get together with others. Find fellowship in the work — it’s essential.

Jeff Stein

How do you reconcile the need for a fight that’s big enough to get enough people involved with the need to organize locally to get change achieved on a small scale?

Zack Exley

Struggle at a local level always exists, and it’s always necessary because there will be these really important conflicts at a neighborhood scale.

A lot of what we put in the book was thoughts about how to make organizing on that scale successful — by asking people to do big things, even at the local level, that will make a big difference in their lives or those of their neighbors.

It’s a challenge. But they exist. The threat of deportation is a great example. People locally can protect their neighbors if Trump moves forward on the threat to deport millions and millions of people. The rise in hate crimes against everybody — people getting organized to change the tone locally would make a huge difference.

What’s the current state of organizing on the left?

Jeff Stein

It seems like one of the real problems for the left is a lack of institutional capacity, and that this is an opportunity to rebuild those organizations at the ground level in response to Trump.

Can you outline the state of organizing on the left — is it true that it’s gotten weaker?

Becky Bond

I’d use a different frame. I wouldn’t say it’s gotten too weak but that it’s gotten too small.

We have some amazingly strong community organizing happening. But it’s clear, based on that we’ve lost all of these legislatures and all of these governorships and all of these states during the Obama administration, that the current community organizing we have is too small.

It’s not reaching enough people to make a difference, which is why we’re organizing for a big organizing approach. If we have a high-quality but small operation and not enough numbers, we’ll continue to fail.

During the Bernie campaign, we learned that there were hundreds of thousands who wanted to get involved — and we were able to build the infrastructure to let them.

After Trump’s election, there are now millions of people who make what we made possible in the Bernie campaign look small by comparison. There’s millions of people that weren’t paying any attention at all during the election — not just people who supported Hillary or Bernie, but so many people just generally against Trump who see the country sliding into fascism.

We need a more scalable type of organizing that allows volunteers to build their own structures without relying on the paid, institutional structures that we have. We need, basically, a lot more to happen — and it’s going to have to come from this latent capacity we know is out there in the grassroots, with people all over the country who may be incredibly talented that can apply it to organizing their communities.

If we do that, the sky’s the limit. And we need that right now, because we’re losing so bad at every level.