Documentaries change in the minds of viewers when they know the outcome before it happens on screen.

Usually it’s the ends justifying the means, the result giving audiences a reason to watch a journey.

Director Rachel Lears didn’t know that the 18 months spent chronicling the lives of four women running as outsider candidates in Democratic primary elections would turn into a Sundance and South by Southwest film festival sensation that would be snapped up by Netflix for a prime time May 1 national release.

Enter Alexandra Ocasio-Cortez, a now-infamous spitfire politician making waves on national news and late night television.

Lears’ film showcases the freshman Congresswoman before the phenomenon, hauling buckets of ice to bartend at a small New York restaurant making it paycheck to paycheck. Knowing what has become of “AOC” makes “Knock Down The House” even more entertaining and engaging, but the heart of this compelling film comes from the struggle.

“Knock Down The House” follows four first-time political candidates – all women running against incumbent Democratic members of Congress – as they embark on a seemingly impossible task of taking on the establishment in hopes of representing the working class.

For close to two years, Lears chronicles the journey of Amy Vilela – a grieving mother challenging for the 4^th Congressional District seat from Nevada, – Paula Jean Swearengin – a coal miner’s daughter fighting for a Senate seat out of West Virginia, – Cori Bush – an African American woman taking on an incumbent for Missouri’s 1^st Congressional District seat in the aftermath of the Ferguson race riots – and Ocasio-Cortez running for New York’s 14^th Congressional District seat amid the political machine stacked against her.

Somewhat surprisingly, “Knock Down The House” doesn’t pit liberals against conservatives. By focusing entirely on the 2018 Democratic primaries, Lears’ film is solely about a movement of political outsiders taking on the establishment rather than issue politics. It’s a challenge to the status quo for lower-case democracy rather than upper-case Democrats.

Ocasio-Cortez best describes this in the film when she says of her primary race: ‘This is not just about Democrat versus Republican. In fact, it’s so far away from that. It’s not Left or Right. It’s up and down.’

“Knock Down The House” does a terrific job of showing the uphill battle outside candidates face while taking down established politicians. Lears includes a number of dramatic moments to reflect this difficulty, most notably Ocasio-Cortez and her team needing to collect over 10,000 signatures from New York voters to help ensure she gets on the ballot despite only being required to collect 1,250.

Lears occasionally struggles with keeping a wide focus to the documentary as the film routinely turns into the Alexandria Ocasio-Cortez show. Balancing a rising star against the other subjects is a tricky endeavor for Lears to manage as Ocasio-Cortez is by far the most dynamic and compelling figure in the entire documentary.

“Knock Down The House” could have very easily been Ocasio-Cortez’s story alone, but there are great moments with the other women running peppered throughout the film that inform and echo the primary story of the film, Ocasio-Cortez’s improbable win over longtime Democratic stalwart Joe Crowley of New York’s 14^th Congressional District.

Notable in their relative absence from the documentary are the subjects’ primary opponents, especially Crowley, who is often represented through television clips and a striking scene midway through the film where Ocasio-Cortez is forced to “debate” a Crowley representative at a Town Hall in the Bronx as Crowley is too busy to be bothered with campaigning for his own re-election.

A phone call between Swearengin and Senator Joe Manchin also sets a real distance between the outsider candidates and their established opponents and helps frame for the audience just how distant these political newcomers truly are.

Lears includes a note within the film’s credits that Crowley, Manchin and Bush’s opponent Lacy Clay all turned down opportunities to appear in the film, which also helps reinforce that establishment candidates do not regard their challengers as being on equal footing.

The film occasionally ties the four women together, both by capturing them at meetings they all attend or in references to how their individual campaigns could help/hurt each other and future candidates in similar outsider situations.

Though it follows progressive Democrats fighting for room in their own party, “Knock Down The House” could just as easily have been a story of conservatives trying to break into the Republican establishment.

The fact that high-quality docs like “Knock Down The House” and the soon-to-be-released “Running With Beto” on HBO later this month are made widely accessible to the public is a great sign for strong independent filmmakers to increase their resolve amid the blockbuster-ization of big screen theaters.

As political documentaries go, “Knock Down The House” is on par with films like “Weiner,” “Citizenfour” and “Get Me Roger Stone” in terms of both quality, compelling cinema and unparalleled, nuanced access to key figures affecting current events on a daily basis.

If it is able to qualify for Academy Awards consideration, “Knock Down The House” is a sure-fire best documentary nominee that moviegoers can breeze through on a casual evening at home, well worth the time spent.