Rep. Alexandria Ocasio-Cortez was the rock star of the Sundance Film Festival — and she didn’t even show up in person.

The New York congresswoman, who represents Queens and the Bronx, features prominently in the new documentary “Knock Down the House,” which had its world premiere at the Festival Sunday night.

During a talk-back after the screening, director Rachel Lears surprised the audience by announcing Ocasio-Cortez would appear live via video conference.

The room roared at the news, which came after one of the most enthusiastic showings of the first week of the festival. Every screening of the film was sold out for weeks before Sundance began, and viewers gave loud ovations whenever Ocasio-Cortez would speak.

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She had been due to attend the premiere and the after-party at the Macro Lounge in downtown Park City, but she canceled the trip at the last minute when President Trump announced the 35-day government shutdown would come to an end.

The documentary follows the campaigns of four insurgent women congressional candidates — Paula Jean Swearingen of West Virginia, Cori Bush of Missouri and Amy Vilela of Nevada — but as the sole victor of the group, Ocasio-Cortez gets the spotlight.

In the first scene, the then-candidate discusses the possibility of losing the election. “Part of me is trying to brace myself,” she says. “People keep telling me, ‘You’ll never be able to show your face in your community again.’”

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She makes many similar comments throughout. Confident on the stump, in private she reveals a prevailing nervousness and paranoia. When canvassing in the boroughs she would come to represent, Ocasio-Cortez gets butterflies in her stomach. “What do you say when they say, ‘Who is it?,’” she asks. “What do you say?!”

At voters homes, she encounters a mix of excitement, indifference and angst. One woman asks Ocasio-Cortez, “Who are you running against?” “Joseph Crowley,” the candidate replies. “No!” says the shocked voter. Another couple sitting on their porch tell Ocasio-Cortez that, although they are Democrats, they voted for Trump in 2016 because of his stance on illegal immigration. The candidate doesn’t respond in the film.

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