Last night, a group of Harvard students kicked off a four-week course dedicated to building skills to take action against Donald Trump’s agenda.

More than 6,500 individuals and groups registered from 50 states and 20 countries for the Resistance School‘s first of four sessions, while 15,000 viewers live-streamed the event.

The course is open to viewers globally, and encourages people to enlist as groups, from full-fledged organizations to potlucks, rather than individuals. “This is a movement moment,” Timothy McCarthy, a Harvard Kennedy School professor who spearheaded the first lecture, told the Crimson. Schools are “places for intellectual exchange, for social transformation, and yes, when necessary, for political resistance,” he said.

Sessions taught by Kennedy School lecturers and political operatives like recently-elected Democratic National Committee Vice Chair Michael A. Blake include “How to Mobilize and Organize our Communities” and “How to Sustain the Resistance Long-Term.” The Kennedy School, where all the founders are students, is the staging ground for lectures but is not formally linked to the project.

Co-founder Joseph L. Breen said the idea came from conversations after the election about how best to stand up to Trump. “We felt like there were a lot of folks who wanted to get involved with political activism but didn’t have the tools to do so,” Breen told the Crimson.

The group is building on a surge in anti-Trump activism, including the Women’s March in January, and a barrage of constituent calls to Congress about everything from Betsey Devos’s appointment as education secretary to the slow dismantling of the Environmental Protection Agency.

The organizing stands counter to pre-election apathy. Only 59% of voters turned up for the US presidential election, slightly more than 2012, but a paltry showing in a highly divisive, ground-breaking race. ”When injustice becomes law, resistance becomes duty,” the Resistance School’s website says. The group has compared itself to Dumbledore’s Army, the covert group in J.K. Rowling’s Harry Potter series who must mater the dark arts to defeat Lord Voldemort.

McCarthy, whose expertise crosses politics and social movements, kicked off the first lecture with “How to Communicate Our Values in Political Advocacy.” His reading list includes a rich collection of essays, mission statements, and founding documents and articles, ranging from Abraham Lincoln’s Second Inaugural Address to Seneca Falls Declaration of Sentiments and Resolutions and “A Vision for Black Lives” (there’s also a values worksheet).

Kennedy School public policy lecturer Marshall Ganz, whose third session covers “How to Structure and build Capacity for Action,” told the Crimson for him the class is about more than just resistance. “It is about turning this into an opportunity to renew our politics.”

Correction (April 6): This post was updated to reflect new figures about the online audience for the school’s first event. The group’s Facebook page says 43,000 people viewed the session, but that is not necessarily how many people streamed it in its entirety.