The headlines are right. Alexandria Ocasio-Cortez, a 28-year-old grassroots activist, just pulled off the biggest upset so far in the 2018 election cycle. Her Democratic primary win Tuesday in a race with Congressman Joe Crowley, a veteran party operative and 10-term incumbent who is the fourth-ranking Democrat in the House, may well be the most remarkable New York City congressional election result since 31-year-old Elizabeth Holtzman beat House Judiciary Committee chairman Emanuel Celler in a 1972 primary.

The defeat of Crowley, who was widely seen as a potential successor to House Democratic leader Nancy Pelosi, was described by a stunned New York Times as “the most significant loss for a Democratic incumbent in years and one that will reverberate across the party and the country.” Ocasio-Cortez won 57.5 to 42.5, despite the fact that Crowley overwhelmingly outspent her and enjoyed support from the same top-ranking Democrats who are lining up to back New York Governor Andrew Cuomo in his September Democratic primary contest with Cynthia Nixon.

Nixon backed Ocasio-Cortez and hailed Tuesday’s win as “what happens when you give people a choice. They show up, and they reject the status quo.”

Matt Blizek, the elections-mobilization director for MoveOn, extended on that theme, saying, “These results are also a shot across the bow of the Democratic establishment in Washington: a young, diverse, and boldly progressive Resistance Movement isn’t waiting to be anointed by the powers that be. Americans from all walks of life who demand change are taking reins of power and showing the Democratic Party what its future looks like.”

The success of a young working-class Latina who served as an organizer for Bernie Sanders in the 2016 presidential race illustrates the volatility that exists within a Democratic Party in which most “leaders” are still too slow to recognize the intense yearning for economic and social change among its own base voters and among the millions of voters who could be rallied to the party line if it offered a dramatically bolder vision. “We were so clear about our values. We were always naming what we wanted to accomplish,” said Ocasio-Cortez, whose primary victory in an overwhelmingly Democratic district all but assures that she will secure the seat in November.

Ocasio-Cortez was warm and open as a candidate—she showed up for the debates that Crowley skipped in the Bronx and Queens neighborhoods that make up New York’s 14th district—yet she pulled no punches when it came to issues. A Bronx native who celebrated her own Puerto Rican heritage, Ocasio-Cortez promised to “fight for sweeping change in the way that the United States relates to Puerto Rico” on a host of economic and enfranchisement issues. In a multiracial, multiethnic district with a large immigrant population, she made the fight against Trump-administration policies central to her campaigning, which highlighted a call for the abolition of the Immigration and Customs Enforcement Agency (ICE). Ocasio-Cortez championed a single-payer, Medicare-for-All health-care system, declared that housing is a right, and called for sweeping criminal-justice reform. And she identified as a proud member of Democratic Socialists of America.

Echoing the slogan of British Labour Party leader Jeremy Corbyn’s movement, she asserted that

In the wealthiest nation in the world, working families shouldn’t have to struggle. It’s time for a New York that’s good for the many. I am an educator, organizer, Democratic Socialist, and born-and-raised New Yorker running to champion working families in Congress. It is well past time that we in NY-14 had a true, lobbyist-free representative who lives in our community and fights on behalf of Bronx + Queens families. This movement for Congress is about education and healthcare; it’s about housing, jobs, justice, and civil rights. It’s is about preparing for the future of our environment, energy, and infrastructure. It’s about championing the dignity of our neighbors. And it’s about getting money out of politics.

That up-front referencing of her democratic socialism signaled that Ocasio-Cortez is a different kind of candidate. She makes no apologies for her ideology.

Asked by Vogue about what drew her to DSA, she offered an activist’s assessment: “(What) I found was that every time I saw myself showing up for something that was important to my community, when I was one of the many people who showed up in Union Square for the 100-day vigil after Hurricane Maria, DSA was there. Every time I was joining my brothers and sisters in the Movement for Black Lives, DSA was there. When I saw these actions, it was like, Okay, this is clearly an extension of our own community. And the thing about DSA is that it’s a very large tent organization.”

But Ocasio-Cortez did not stop there. She went into details about how a socialist vision might be framed in 21st-century America:

When we talk about the word socialism, I think what it really means is just democratic participation in our economic dignity, and our economic, social, and racial dignity. It is about direct representation and people actually having power and stake over their economic and social wellness, at the end of the day. To me, what socialism means is to guarantee a basic level of dignity. It’s asserting the value of saying that the America we want and the America that we are proud of is one in which all children can access a dignified education. It’s one in which no person is too poor to have the medicines they need to live. It’s to say that no individual’s civil rights are to be violated. And it’s also to say that we need to really examine the historical inequities that have created much of the inequalities—both in terms of economics and social and racial justice—because they are intertwined. This idea of, like, race or class is a false choice. Even if you wanted to separate those two things, you can’t separate the two, they are intrinsically and inextricably tied. There is no other force, there is no other party, there is no other real ideology out there right now that is asserting the minimum elements necessary to lead a dignified American life.

While this win is the highest-profile one for a candidate backed by DSA—and, it should be noted, Justice Democrats, Our Revolution, MoveOn, and Democracy for America—it was not the first in the period since Sanders renewed the historic American democratic-socialist ideal with his 2016 campaign. Sanders hailed Ocasio-Cortez’s “extraordinary upset victory,” highlighting the fact that “She took on the entire local Democratic establishment in her district and won a very strong victory. She demonstrated once again what progressive grassroots politics can do.”

Christian Bowe of DSA’s National Political Committee shared that sentiment.

“Tonight’s victory shows that we are in the middle of a political revolution,” said Bowe. “By running on an unabashedly Democratic Socialist platform focused on healthcare for all, housing as a human right, abolishing ICE, justice for Puerto Rico and a federal jobs guarantee, Ocasio-Cortez was able to defeat a powerful establishment Democrat who has been in Congress since 1999. The people of NY-14 demanded more from its representative than empty promises and deep pockets. We’re proud of this victory, and we know this is only one of many more to come.”