What do former GOP Rep. Adam Kinzinger and the 'far left' director of 'Hot Tub Time Machine' have in common? A lot, it turns out.

The 2010 comedy Hot Tub Time Machine, about four friends who get the chance to relive an important night in 1986, has probably not been mentioned in many documentaries — let alone a political documentary.

But in The Last Republican, when former Republican Rep. Adam Kinzinger is asked why he agreed to have the film’s director, Steve Pink, help produce the documentary about his career in the aftermath of the Jan. 6, 2021, Capitol attack, Kinzinger smiles and says, “Hot Tub Time Machine’s the thing that sold me.”

Pink’s slapstick buddy comedy is not just one of Kinzinger’s favorite movies, but it serves as a sort of metaphor for the common ground between the former Republican congressman and the self-described “far left” Democratic director that is at the heart of the film. The Last Republican, which premiered in New York on Jan. 3, follows Kinzinger’s final year in Congress as one of two Republicans to serve on the House select committee investigating the Capitol attack, and the isolation he says he experienced from the rest of his party.

Pink, whose other film and TV credits include High Fidelity, Accepted and the Netflix shows Santa Clarita Diet and Cobra Kai, said he was initially hesitant when one of his colleagues suggested reaching out to Kinzinger about a documentary.

“I was feeling [like] a bit of a jerk about it because I’m on the far left,” Pink told Yahoo News. “I knew [Kinzinger] was courageous, but I don’t really want to do a documentary about a conservative Republican.”

In the opening scene of the documentary, Kinzinger immediately addresses the political divide between himself and Pink.

“You have contempt in what I believe, in terms of my political viewpoints,” Kinzinger tells Pink, who is standing off camera. “I think in any other situation, you’d probably be protesting my office.”

At a time when Americans are finding it increasingly difficult to talk about politics with people who disagree with them, Pink and Kinzinger hope that The Last Republican can serve as a model for healthy civil debate. Throughout the film, the audience is given the chance to witness a number of political debates between Pink and Kinzinger, in which they are able to laugh and poke fun while calling each other names like “right-wing fascist” and “left-wing communist.” Though neither successfully convinces the other to agree with his political point of view, a genuine friendship emerges despite their differences.

“What we realized — because it was something that evolved naturally, between Adam and I — is that the movie became as much about the need for civil discourse as a profile in courage,” Pink said.

In the film, Kinzinger, who represented Illinois in Congress for 12 years, explains that he has always identified as a Republican, even as a young kid growing up in Florida. He was inside the Capitol on Jan. 6 when a violent mob of Donald Trump’s supporters stormed the building in an attempt to prevent the certification of Joe Biden’s 2020 electoral victory.

After Jan. 6, Kinzinger was one of only 35 House Republicans who voted in favor of investigating the attack, and one of just 10 who voted to impeach Trump. He and then-Rep. Liz Cheney, of Wyoming, were the only two Republicans appointed to the select committee that investigated the attack.

The film documents how Kinzinger’s decision to speak out against Trump and the events of Jan. 6 impacted his relationships with other Republicans in Congress, and the threats he and his staff received as a result.

“The fact that, after that, he agreed to let us make a documentary about him, it just showed a lot of courage on his part,” Pink said.

While the film is centered around one of the most contentious political moments in recent history, both Kinzinger and Pink are hopeful that the story of their friendship can encourage viewers to put politics aside and learn to bridge that divide in their own lives.

“We live in a time where we’re not talking to each other, we live in different realities,” Kinzinger said. “We need this example of how to actually live together and understand each other to begin to walk us off the ledge.”