WASHINGTON, D.C.— In the middle of the National Mall, on the same spot that had, the day before, hosted the revelers who had come out for the inauguration of Donald Trump, a crowd of people protesting the new presidency spontaneously formed themselves into a circle. They grasped hands. They invited others in. “Join our circle!” one woman shouted, merrily, to a small group of passersby. They obliged. The expanse—a small spot of emptiness in a space otherwise teeming with people—got steadily larger, until it spanned nearly 100 feet across. If you happened to be flying directly above the Mall during the early afternoon of January 21, as the Women’s March on Washington was in full swing, you would have seen a throng of people—about half a million of them, according to the most recent estimates—punctuated, in the middle, by an ad-hoc little bullseye.

“What is this circle about?” a woman asked one of the circle-standers.

“Nobody knows!” the circle-stander replied, cheerfully.

The space stayed empty for a moment, as people clasped hands and looked around at each other with grins and “what-now?” expressions. And then: A woman ran through the circle, dancing, waving a sign that read “FREE MELANIA.” The crowd nodded approvingly. Another woman did the same with her sign. A group of three teenage boys danced with their “BAD HOMBRE” placards. The crowd whooped. Soon, several people were using the space as a stage. A woman dressed as a plush vulva shimmied around the circle’s perimeter. The circle-standers laughed and clapped and cheered. They held their phones in their air, taking pictures and videos. They cheered some more.

The Women’s March on Washington began in a similarly ad-hoc manner. The protest sprang to life as an errant idea posted to Facebook, right after Trump won the presidency. The notion weathered controversy to evolve into something that, on Saturday, was funereal in purpose but decidedly celebratory in tone. The march, in pretty much every way including the most literal, opposed the inaugural ceremony that had taken place the day before. On the one hand, it protested President Trump. Its participants wore not designer clothes, but jeans and sneakers and—the unofficial uniform of the event—pink knit caps with ears meant to evoke, and synonymize, cats. It had, in place of somber ritual, a festival-like atmosphere. It featured, instead of pomp and circumstance, people spontaneously breaking into dance on a spontaneously formed dance floor.

And yet in many ways, the march was also extremely similar to the inauguration whose infrastructure it had co-opted, symbolically and otherwise, for its own purposes. The Women’s March on Washington shared a setting—the Capitol, the Mall, the erstwhile inaugural parade route—with the ceremonies of January 20. And, following an election in which the victor lost the popular vote, the protest seems to have bested the inauguration itself in terms of (physical) public turnout. During a time of extreme partisanship and division—a time in which the One America the now-former president once spoke of can seem an ever-more-distant possibility—the Women’s March on Washington played out as a kind of alternate-reality inauguration: not necessarily of Hillary Clinton, but of the ideas and ideals her candidacy represented. The demonstrations were an installation ceremony of a sort—not of a new president, but of the political resistance to him.

“I DO NOT ACCEPT THIS FILTHY ROTTEN SYSTEM,” read one sign, carried by Lauren Grace, 35, of Philadelphia. She got the quote from Dorothy Day. And she intended it, Grace explained to me, to protest “a system that sort of left me out.”

“We’re told that voting is a sacred right in this country,” Grace said. “But even though Hillary won the popular vote, she still lost. I feel pretty conflicted about a country where that could happen.”

The Women’s March on Washington was, to be sure, also a protest march in an extremely traditional vein: It featured leaders—celebrities, activists, celebrity activists—who gave speeches and offered performances on a stage with the Capitol in its background; its participants held signs, and chanted (“This-is-what-a-feminist-looks-like!,” “No-person-is-illegal!”), and commiserated. It was also traditional in that its participants were marching not for one specific thing, but for many related aspirations. Women’s reproductive rights. LGBTQ rights. Immigration rights. Feminism in general (“FEMALES ARE STRONG AS HELL,” one sign went, riffing off a famous feminist’s Netflix show). The environment (“CLIMATE CHANGE IS REAL,” “MAKE THE PLANET GREAT AGAIN”). Science (“Y’ALL NEED SCIENCE”). Facts (“MAKE AMERICA FACT-CHECK AGAIN”). Some signs argued for socialism. Some argued against plutocracy. Some argued for Kindness. Some pled for Peace. Some simply argued that America is Already Great.

This was a big-tent protest, in other words—a messy, joyful coalescence of many different movements. The Women’s March on Washington deftly employed, in its rhetoric, the biggest of the big-tent tautologies: The point of this protest wasn’t so much the specific things being protested as it was the very bigness of the crowds who were doing the protesting. This was another way the protest alternate-realitied the presidential inauguration: Just as the official ceremony is meant to celebrate not only the person occupying the presidency, but the presidency itself, the Women’s March was a protest that celebrated protest.

In doing that, it took direct aim at the things the new president has a record of valuing so highly—crowd sizes, ratings, large-scale approval—and countered them. Trump, after all, since the beginning of his presidential candidacy, has made a point of emphasizing the size of the crowds he has been able to attract by way of celebrity’s gravitational pull. He has boasted about the throngs attending his rallies. He has taunted his opponents about the relatively few people who turned out for their events. And Trump’s ascendance to the presidency seems to have done nothing to assuage that impulse: On Friday evening, at the Armed Services Ball, Trump again talked about the large size of the crowd that had come to witness his inauguration. And on Saturday, Press Secretary Sean Spicer used his first official White House briefing to blast the media who had mentioned the size of Trump’s inauguration crowds as compared to those of past presidents, dismissing their assessment as attempts to “minimize the enormous support” that had gotten Trump elected. (Though crowd sizes are notoriously difficult to determine with precision, Trump’s crowds were in fact decidedly smaller than the ones that came out for Barack Obama’s first inauguration in 2009.)

The new president, in his rhetoric, has emphasized the “pop” in “populism.” And so—counterpunch—the Women’s March on Washington has emphasized its own crowd size. The throngs on Saturday spilled over from the march’s stage, where celebrities (America Ferrera, Gloria Steinem, Janelle Monáe, Katy Perry, Ashley Judd, Alicia Keys, Madonna) and activists (Rise’s Amanda Nguyen, the Natural Resources Defense Council’s Rhea Suh, Our Revolution’s Erika Andiola, and many others) spoke to the people watching them both in person and on TV; they marched down Independence Avenue, and milled down Pennsylvania Avenue; they piled onto the steps of the National Gallery of Art; they filled the Mall to capacity. They showed up to sister rallies around the country and the world—in Chicago, in Boston, in New York, in Los Angeles, in Barcelona, in Nairobi, in New Delhi. And according to the march’s organizers, CNN reported, “the crowds were exponentially larger than expected.”

According to organizers, too: That matters. If the Women’s March on Washington was trying to inaugurate a movement on January 21, 2017, the first thing it had to do was to prove that there was a movement to be inaugurated. As one sign read: “TRUMP, DO YOU REALLY WANT TO PISS OFF THIS MANY WOMEN?”

Or, as Raquel Willis, of the Transgender Law Center, told the audience before she began the rest of her speech on the march’s main stage: “I want us to take a second and look around. Look at all these people who are gathered here to take a stand. These are your partners in resistance and liberation.”

Monáe made a similar argument. “This is about all of us,” the actor and singer said, “fighting back against the abuse of power.”

“All of us.” “Us” is a tricky word in the America of 2017, the America that is coming off of an acrimonious campaign season—with all its offenses, on all sides, still fresh. But the Women’s March on Washington insisted that the “us” and the “we” are two other things to be reclaimed in the years ahead—two other things that will be at stake in every peaceful transition of power. As Ferrera told the crowd at the beginning of the protest, “The president is not America. His cabinet is not America. Congress is not America. We are America. And we are here to stay.”