Activists planning the People’s Climate March in Washington, D.C. on April 29 are mapping out a far more ambitious trek than that day’s walk from the Capitol to the White House. They are trying to turn rage over the Trump administration’s rollback of climate change policy and budget cuts targeting science into actual political clout.

Tens of thousands of demonstrators organized by 50 groups that represent millions of members plan to demand that political leaders preserve protections for the environment and public health and invest in a clean energy economy. The march will culminate a week of activism that begins with the March for Science on April 22, followed by lobbying visits on Capitol Hill, rallies outside federal agencies and national and local candidate training workshops. There will be more than 250 People’s Climate Marches held across the country and overseas.

The march will be the first major demonstration of how the climate movement is regrouping since the election last November, when Republicans not only won the White House but also nearly every Congressional race that environmental groups had tried to sway. In the first 100 days of the Trump administration, activists have witnessed the dismantling of climate and environmental policy.

They have protested, to no avail, someone who denies basic climate science being named to head the Environmental Protection Agency and a former oil executive to lead the State Department. The Clean Power Plan has been targeted for elimination, every federal climate science and research program is in jeopardy, the Keystone XL and Dakota Access pipelines have been approved, and U.S. participation in the Paris climate agreement is uncertain. March organizers are grappling with how to mount effective resistance against the assault.

“A march is great and all—it’s great to show power and show force,” said Mike Williams, vice president of the Blue-Green Alliance, a labor-environmental coalition and one of the march’s organizers. “But a lot of the focus is on how do we turn this into a true big, deep movement-building effort?”

Polls indicate growing public understanding of the climate change problem, with 76 percent of American voters calling themselves “very concerned” or “somewhat concerned” about global warming, according to a recent Quinnipiac University Poll. But the movement has not been able to turn climate action into a voting issue, even as public protests, particularly against fossil fuel infrastructure projects, swell and spread nationwide.

Activists’ hope now is that the Trump administration’s actions are a wake-up call that convinces people who care about climate change to become politically engaged.

“A big part of it is about voicing massive opposition to the Trump administration and their rollbacks on climate action,” said Maura Cowley, associate director of the federal and international climate campaign for Sierra Club. “But I think this event is galvanizing the movement in other ways. We have communities from across the country that have been directly impacted by climate change or the fossil fuel industry involved. We’re seeing people across the country really looking deeply into what their cities and towns and states can be doing to address climate change, and trying to build a buffer at the local level to Trump’s attacks.”

Climate activists had selected April 29 as a day of mobilization long before they knew that they’d be locked in battle with the Trump administration. Planning began last summer, with People’s Climate March organizers hoping to reprise a 2014 protest in New York, when more than 400,000 people took to the streets ahead of a United Nations summit. It was the largest climate march in history. Organizers believe that the outpouring had helped prod President Obama and set the stage for the Paris accord the following year.

A steering committee with representatives from 50 environmental, religious, labor and social justice organizations, now holds conference calls twice a week. In addition to climate advocacy group 350.org and environmental groups like Sierra Club, the League of Conservation Voters, NextGen Climate and Moms Clean Air Task Force, groups include the NAACP, the Hip Hop Caucus, more than a half-dozen labor organizations and faith groups like the Franciscan Action Network. Separate conference calls of break-out groups focus on fundraising, side events, art and music, publicity and outreach. More than 100,000 people have RSVP’d to march, but organizers say that although turnout will be an important measure of their success, they want more than numbers.

“We just had a call about making sure we had representation from everywhere—even Alaska and Hawaii,” said Paul Getsos, People’s Climate March national coordinator. “The most important priority we have is the broad base—building the broadest coalition possible. We want to invest in the eight buses from historically black colleges in Atlanta, Georgia. We want to make sure we have representation from Louisiana, which is so impacted by climate change.”

The march organizers don’t have a list of demands. Getting agreement from so many organizations would be difficult, and Getsos said the People’s Climate March aims to be a “big tent” that can accommodate diverse views.

The rallying cry is anti-Trump sentiment. “These dangerous and regressive steps by the administration are motivating people who are looking for a way to fight back,” said Lindsey Meiman, spokeswoman for 350.org.

“Sierra Club Thanks Donald Trump for Helping People’s Climate March Recruitment,” the organization said in one recent press release. The Sierra Club also is investing in its own publicity; it released an ad for the march directed by Hollywood producer Darren Aronofsky that mixes scenes of natural beauty with threats from oil spills, pollution and extreme weather.

Mark Magana, founder and chief executive of Green Latinos, said his group participated in the 2014 march in New York, but decided it wanted a bigger role, and is on the steering committee for this march. Noting that 2 in 5 Latinos live within 30 miles of the fenceline of a power plant and will suffer disproportionately from the Trump administration’s planned rollbacks in clean power, he said, “We wanted to make sure that we leveraged this opportunity and this moment for the fenceline communities. To place those issues front and center in all aspects of this march for us it was absolutely critical that we lend our help in this capacity.”

March organizers also are coordinating with organizers of the March for Science planned for April 22 (Earth Day) in Washington, D.C., with 400 sister marches in cities worldwide. More than 170 partner organizations, including the American Association for the Advancement of Science and American Geophysical Union, are supporting the march to protest budget cuts and censorship of research.

The science march is pointedly non-partisan; organizers said no politicians will speak at the event. Instead, there will be scientists like Mona Hanna-Attisha, the pediatrician who helped expose dangerous lead levels in drinking water in Flint, Mich. There also will be small-group teach-ins on science and its benefits. “We’re trying to channel the momentum behind the march from the initial engagement of people taking to the streets to a sustained and coordinated science advocacy,” says Caroline Weinberg, national co-chair of the March for Science. “Because the march isn’t going to change anything unless we keep it going beyond April 22.”

Another way the People’s Climate March organizers hope to keep the movement going is to encourage greater local political involvement.

Organizers are planning a training session for April 30 for 200-300 activists who have been inspired to run for local and state offices. “I think the environmental movement is faced with a new reality in light of Trump,” said Whit Jones, director of Lead Locally, which is coordinating the training. “It’s going to be very challenging at the national level, and in order to continue to make progress, our opportunities lies within the state and local level. City governments and states can protect against fossil fuel infrastructure and can lead on renewable energy.” Jones said the group hopes to identify key local elections that climate activists can target this year.

A separate training session for pro-environment women who want to run for office is being offered by EMILY’S List and a coalition of environmental and women’s groups.

March organizers in Los Angeles also are focusing on Tesoro’s plans to create the largest oil refinery on the West Coast with the combination of two of its facilities on the southern shore of Santa Monica bay. The route of the march is from Banning Park to the Tesoro refinery. “Climate change starts in our hoods,” said an ad promoting the march by SoCal 350.org.

Williams of the Blue-Green Alliance said that such grassroots organizing is the only way the movement will be able to build the political clout it needs.

“Why aren’t we making those in power fear our power? I think truly it is because we have not done a good enough job of true local grassroots organizing—of going out and talking to human beings,” he said. “Even in places where we are not met kindly. We need to be talking to people, person to person.”