“I need to take up space,” Alexandria Ocasio-Cortez proclaims in Knock Down the House, a rousing documentary that had its world premiere at Sundance this week. She’s preparing for a debate against 10-term incumbent Joe Crowley, and as she runs through her list of affirmations, she waves her arms in front of her, as if carving out a place in the world for her to occupy. But the line, as it’s intended to, resonates beyond that moment—and even beyond Ocasio-Cortez’s already-legendary run, which made her the youngest woman serving in Congress and, even before she took office, one of the most visible political figures in America.

Ocasio-Cortez isn’t the only one to take up space in Rachel Lears’ documentary, which also follows three other would-be insurgents in the 2018 Democratic primaries. Paula Jean Swearingen is a West Virginian running to unseat incumbent Sen. Joe Manchin, who took millions from coal companies in one of the country’s poorest states and crossed party lines to vote for Brett Kavanaugh’s confirmation. Cori Bush is a black woman in St. Louis aiming to end a father and son’s 50-year hold on a congressional seat. And Amy Vilela, whose daughter died after she was turned away from a hospital for lack of health insurance, is pushing Medicare for All in Las Vegas. All three, along with Ocasio-Cortez, were backed by the organizations Brand New Congress and Justice Democrats, whose goal is to transform the Democratic Party by replacing ossified incumbents with progressive challengers, especially women and people of color with no previous political careers. As one adviser tells Bush, “No one owns you—yet. You don’t owe anyone anything—yet.”

Ocasio-Cortez is obviously the movie’s main draw, and might have been even if not for her historic electoral victory. As she continues to demonstrate on social media, she’s an expert at playing to the lens, whether it’s attached to a video camera or an iPhone. She’s an engrossing subject, no matter if she’s scooping up ice at her former bartending job or raging against economic inequality. One of the most thrilling scenes in Knock Down the House is when she furiously dissects one of Crowley’s campaign mailings, an elaborate four-page foldout with an airbrushed photo of him taking up its entire cover. “Where’s Election Day?” she says, holding up one of her own mailers, a double-sided card with a cleanly delineated graphic design that prominently displays the day her supporters should head to the polls. “Where’s the date?” She rips apart the Crowley mailing’s emphasis on vague promises to “deliver” for his constituents—“that means pork”—and when she gets to the part where it claims he’s “leading the fight against Donald Trump,” she shoots the camera a look so withering it would make Jim Halpert flinch.

You can almost see the moment Ocasio-Cortez’s opponent realizes he’s in trouble.

Ocasio-Cortez eventually meets Crowley face to face, although only after the New York Times has called him out for skipping their debates by cynically sending a woman of color to act as his surrogate. (Ocasio-Cortez threads a delicate needle by thanking the surrogate for her public service while blasting Crowley for skipping out.) You can almost see the moment when Crowley realizes he’s in trouble, even though the polls had him a heavy favorite until Election Day: It’s when she brings up the fact that the Democrats have lost over 1,000 seats nationwide, as well as the presidency and both houses of Congress. He shifts in his seat as she talks, unbuttons his shirt sleeves and starts rolling them up in the middle of a debate, attempting to slip into the old-school uniform of the politician who’s working hard for you. But after watching Ocasio-Cortez and the other women in Knock Down the House pound the pavement and knock on doors, you can see that they’re the ones working hard, and that for them, getting their hands dirty is nothing new.

Even Crowley recognizes Ocasio-Cortez’s “energy,” and it would be easy to tag to the movie’s other subjects, all of whom lost their races, with the same vaguely patronizing term. But they are adamant that they’re not protest or single-issue candidates, merely running to nudge centrist incumbents slightly to the left. They’re in it to win it, against long odds that nonetheless sometimes fall in their favor. Swearingen isn’t flattered or surprised when Manchin calls the night of his win to ask her to sit down with him; it’s about time. Their defeats are heartbreaking, not least for the young staffers who (sometimes sparsely) populate their campaign centers. But they’re moving in the right direction, and if they don’t get across the line, they’ve beaten a path for the people who helped them run.

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