Welcome to the AOC primary. At 29 years old, Congresswoman Alexandria Ocasio-Cortez — already known as “AOC” for short — is too young to be eligible to run for US president.
But her phenomenal impact on American politics means that she could play an outsized role in deciding who does.
As her fellow Democrats jostle for position ahead of the 2020 primary elections, an endorsement from Ocasio-Cortez is likely to be a widely coveted prize, a guaranteed shot of adrenaline sure to energise her army of millennial voters.
But it could also come with perils in the later presidential contest, especially for so-called “centrist” candidates hoping to draw independents and moderate Republicans away from Donald Trump.
In little more than a month, Ocasio-Cortez, whose New York district includes parts of the Bronx and Queens, has taken Washington by storm,
overshadowing career politicians who have spent years labouring in the 435-member House of Representatives.
Her proposals — among them a Green New Deal to combat climate change and a 70% tax rate on earnings over $10mn to tackle economic inequality — have reset terms of debate in the early stages of the Democratic contest.
“This is a race to the left,” said Dave Handy, a New York-based political consultant and organiser. 
“Even if people don’t like her or her policies, they will be racing to get her endorsement because it’s a progressive check mark. She embodies the general direction the party is going in.”
Ocasio-Cortez is also a social media sensation.
She has in excess of 3mn followers on Twitter with more engagement than Donald Trump, Barack Obama or Vermont senator Bernie Sanders.
Last week a video clip in which she quizzed ethics experts about government corruption became the most watched political video ever posted on Twitter with 37.5mn views.
It was another demonstration of astonishing clout.
Neil Sroka, communications director of the progressive group Democracy for America, said: “She’s built a profile with a savvy way beyond her years, but she also has an agenda that feels right for the moment. AOC does not exist without the bold, inclusive, populist agenda she’s pushing. The vitriol she has inspired speaks to how afraid everyone is; Republicans see her as representing a country they don’t even know how to speak to.”
Experts predict that, by polling day in November 2020, millennials will have overtaken baby boomers to become the biggest voter eligible age group.
Sroka noted: “Millennials are not a young age group any more. I’m 35 in April and I’ve got a wife, a child and a house in Michigan. AOC is 29 and speaks to the range of millennial experiences. There is no one national figure more directly attractive to millennials and that’s what makes her such a potentially powerful endorser in the primary.”
Eleven Democrats have already declared they are running for president and more are poised to join a fiercely competitive race in which endorsements could matter more than usual.
Senator Kamala Harris has already gained the backing of California representative Barbara Lee, former chair of the Congressional Black Caucus, and Katie Hill, a 31-year-old freshman, while Massachusetts senator Elizabeth Warren got the nod from Representative Joe Kennedy III, grandson of Robert F Kennedy.
Other potentially valuable endorsements up for grabs include vice-president turned climate activist Al Gore, former secretary of state and Democratic nominee John Kerry, ex-president Barack Obama and TV personality Oprah Winfrey.
Then there is Bill and Hillary Clinton, whose patronage might be seen as a mixed blessing.
But most are likely to stay on the sidelines until the contest becomes clearer.
John Zogby, a Democratic pollster and author, said: “Somebody who says, ‘I can deliver my followers’ takes on a huge role. In such a crowded primary, anyone who can move a few thousand votes is important.”
The candidate whom Ocasio-Cortez is most likely to endorse is not yet in the race: Sanders.
Ocasio-Cortez was an organiser for his insurgent 2016 primary campaign against Hillary Clinton.
She has credited her fellow progressive for inspiring her, while working as a bartender, to go into politics and pull off a stunning win against a 10-term incumbent to win her seat in Congress.
They have appeared on joint platforms and given interviews to champion their shared Democratic socialist agenda.
Zogby commented: “There’s an old Chicago politics saying: ‘You dance with the one that brung ya,’ … If he gets in the race, it would be difficult for her not endorse him.”
So far, however, Ocasio-Cortez has declined to throw her weight behind Sanders or any other progressives in the 2020 race.
Interviewed on MSNBC’s Meet the Press Daily last week, she said: “I love Senator Sanders. I think he’s great and I think in terms of, like, an endorsement, I joke. I say, ‘Don’t ask me until the day of the New York primary’. But I think the important thing that we need to realise is, I hope, we use this primary not as a horse race around personalities but around our values.”
Centrist candidates, expected to include former vice-president Joe Biden, are not likely to seek or receive Ocasio-Cortez’s backing.
Fox News and other conservative media have mocked the Green New Deal and sought to portray her as a novice radical who would put the country on a dangerous path.
As Ocasio-Cortez looked on smiling, Trump offered a preview in his state of the union address of how he will conjure the spectre of Venezuela-style “socialism” in the Democratic party ahead of 2020.
Larry Sabato, director of the Center for Politics at the University of Virginia, said: “Her endorsement will be coveted but she has most influence with the left and especially young people. The eventual nominee will probably say: ‘I agree with her on some things and not on others.’ The nominee probably will be centre-left because Democrats really yearn to unseat Trump. If they lose sight of that, it’s four more years of him.”