NEW YORK • At the Parkchester apartments in the Bronx, neighbours heard the news from a maintenance worker: The woman down the hall had just won a Democratic primary and was probably destined for Congress.

At a popular restaurant in Union Square in Manhattan, workers struggled to comprehend that the young politician whose face was all over TV really was the same woman who had tended bar until a few months ago. And on the streets of midtown Manhattan last Wednesday, the candidate herself was trying to make sense of it all.

"I'm used to people kind of knowing me in the community," said Ms Alexandria Ocasio-Cortez, 28. But to have random people ask to take a selfie with her? "Insane."

Ms Ocasio-Cortez, whose resume up to now included waitress, children's book publisher, community activist, member of the Democratic Socialists of America and former Bernie Sanders campaign organiser, was now something else: An instant political rock star.

She stunned the Democratic establishment by beating one of the senior leaders in the House, Mr Joseph Crowley, in a near-landslide in last Tuesday's primary.

She is expected to have little difficulty defeating the Republican candidate, Mr Anthony Pappas, in a predominantly Democratic district that takes in working-class, immigrant-heavy swaths of the Bronx and Queens in November.

Behind the scenes, of course, Ms Ocasio-Cortez's rise has been a little less sudden. "For two years," she said, "all I have been thinking about is 8.59 on June 26", when the polls closed last Tuesday night.

But it goes back many years before that. As a teenager, she never hesitated to speak her mind during political conversations around the dinner table.

"There was nobody who could shut her up," said her mother Blanca Ocasio-Cortez. "I saw the political tendencies since she was very, very young."

Ms Ocasio-Cortez's mother was born in Puerto Rico. Her late father, Mr Sergio Ocasio, an architect, was born in the Bronx. In high school, Ms Ocasio-Cortez was a serious science student and won second place in the Intel International Science and Engineering Fair in 2007.

Her science teacher Michael Blueglass said that even as a teenager, she looked at science through a political lens. "She was interested in research to help people in all areas, including developing nations."

Ms Ocasio-Cortez went off to Boston University. After her father died in her sophomore year, she threw herself into studying. "She jumped from having good grades to being on the dean's list," her mother said.

She majored in economics and international relations. She also dabbled in establishment politics, working for Democratic Senator Edward Kennedy on immigration, but soon turned her attention to the grassroots work that would come to define her candidacy.

Returning to the Bronx after graduation, she began advocating improved childhood education and literacy, starting a children's book publishing company that sought to portray her borough positively.

She returned to national politics when she worked as an organiser for the Sanders campaign.

She credited her decision to seek office with her experience protesting at the Standing Rock Sioux Tribe reservation in 2016, against the Dakota Access Pipeline. Around that time, she was contacted by Brand New Congress, a newly formed progressive organisation that asked her to run.

She continued working until February behind the bar at Flats Fix, a taco restaurant in Union Square, going to political meetings and fund-raising parties after her shift.

"I spent the entire first part of this campaign just going to people's living rooms and having them invite their neighbours, and just doing little coffee parties for like six or seven months," she said.

Her campaign evolved into a digital and door-to-door crusade. She used Facebook, Twitter and Instagram to turn out new voters and push a progressive message that included calls for tuition-free public colleges, Medicare for all, and the abolition of the Immigration and Customs Enforcement agency.

On primary day, on her way to a Bronx billiard hall to watch the results, she passed by a screen that showed her in the lead. "I just started running," she said. "I literally ran and I busted through the doors."

NYTIMES