In June of 2012, Kimberly Reed was waiting outside the Supreme Court as a 5-4 judgment was being handed down in the case of American Tradition Partnership and Western Tradition Partnership vs. Bullock, a decision that would reaffirm the High Court’s controversial ruling in the case of Citizens United v. the Federal Election Commission, in which political campaign contributions were regarded as free speech and therefore not subject to limitations. The Court’s policy of not allowing cameras in to film were an obvious obstacle for Reed, but one that wasn’t insurmountable — the resourceful filmmaker has a way of finding the detail that can turn the abstract into something you can hold onto as an audience.

“I was lucky enough to find a sketch artist sitting in a picaresque manner on the steps of the Supreme Court,” says Reed now with a bit of a laugh, managing to also snag a shot of an American flag growing obscure during the same shoot to capture the national mood. “It was pretty cool.”

Time and again, this skill would come in handy on “Dark Money,” an invigorating look into the insidious infusion of anonymous campaign contributions into local politics by private interests likely looking to enrich themselves. While the implications of shadowy campaign financing can remain obscure not only by design but in how complex and arcane it can be to explain, Reed brings the practice into sharp relief by shining a light on her home state of Montana where the desire to keep out-of-state money from entering their elections dates back to the turn of the 20th century, when the Corrupt Practices Act was passed in the state in 1912 after copper barons sought to infiltrate all levels of government to secure control of the state’s natural resources. A century later, the law, which has been the strongest campaign finance law in country since being put on the books, gave the state’s Attorney General — now-Governor — Steve Bullock the basis for the best case to overturn Citizens United, yet when it went down in defeat, Reed was undeterred in learning more about the defendants, the Western Tradition Partnership, and teams up with John Adams, a dogged reporter who covers the state capitol for The Great Falls Tribune to follow the money.

Over the course of six years, Reed and Adams’ systemic investigation of Montana’s election infrastructure in a state where both parties endorse strict campaign finance laws reveals a number of deeply concerning issues that reach well beyond Billings and Helena in terms that truly bring them home, exposing corrupt politicians who have no interest in serving the public and have been all but placed into power by corporations eager to exploit the land and the erosion of protections to what laws there are on the books, whether it is staffing of government officials dedicated to election oversight or a free press that even when not dealing with issues of access are fighting against constant cutbacks that make their careers unsustainable. Although the scope of the film is broad, it’s Reed’s ability to keep the focus narrow and to convey the very tangible and damaging impact that unlimited and unknown campaign donors are having at all levels of American government and as the must-see film makes its way into theaters following its premiere earlier this year at the Sundance Film Festival, Reed, who previously made the powerful personal documentary “Prodigal Sons” about her return home after gender reassignment surgery, spoke about the pride and inspiration she takes in being from Montana, committing to such a long-term project and her unique relationship with Adams as resource for her film who became a subject of it.

John S. Adams in "Dark Money"How did this come about?

I heard about Citizens United. It didn’t make sense to me on its face and it presented a lot of questions [that] jumbled around [in my head] until 2012, at which point I saw my home state had a case that had the ability to challenge and perhaps overturn Citizens United. So I realized this is a really fundamental issue that sits beneath all other political issues and [the Montana case] is the way to tell it because there were a lot of people talking about Citizens United and the impact of money in politics, but this would be a way to tell it with humans and not abstract concepts. I got drawn back to Montana to follow this story as it kept breaking and as you see in the film, it’s like you dig a little bit and it makes you want to dig more and this story just kept unfolding and getting more and more interesting. Every rock you would lift up, you would find something else. It took me about six years to make the film in service of telling the story of money in politics through people, and Montana was the best case study because there’s a strong historical tradition of paying attention to these issues.

I’m glad you didn’t, but since this is such a large issue nationally, was the temptation there to take a broader view?

Sure. It’s an enormous issue. You see it breaking all over the place just within the last couple days and there’s a lot of different ways to do it. But just as a storyteller, I think the way to do it is just to focus on a microcosm — and you saw the same thing in “Prodigal Sons.” It’s also a little bit more practical. These stories about money in politics get pretty complicated pretty quick and if you shoot off into a bunch of different directions and add too many details, people’s eyes glaze over and you lose the drama in the story because you get lost in all of the complexity of it. I wanted to make sure that we didn’t do that. And Montana was the best [place] to look at because with a lot of these money in politics issues, you never see a dramatic clash. You never see one side standing up and saying, “Yes, I believe in these dark money groups and this is how our elections should run!” And in Montana, you have this group of people defending Citizens United and you see the other side of that clash, which is people standing up and saying, “No, this stuff matters to us. We’re paying attention to it and we’re going to vote on it. We care about it as a society.” The fact that these two opposing forces were coming together seemed to be a very unique combination of events that was taking place, so I had no choice but to keep following it.

A scene from Kimberly Reed's "Dark Money"How does John Adams become the person to follow?

There were three or four different journalists who were really following money in politics and he was one of them, so I was very familiar with his reporting because I had been using it as a resource. Initially, it was just that — he was my source, but as I proceeded a bit with the film, I thought it would be just a really good idea to have him as a narrator — not a narrator in a traditional sense, but somebody whose eyes we could see this drama through. I met him about a year into filming and he went on camera after about two years of filming — [because I had to] I convince the reluctant journalist who didn’t want to be part of the story, to actually be part of the story — and from then on, it really blended into one by the end and we both were chipping away at the same story together — I was following this big, slow-burn story that was going to take years and he was filing these day to day stories, and he just happened to be the person on camera explaining it. But it was an interesting dynamic. We were always following the same story. It was just a matter of putting him on camera to help us do that.

With a long-term project like this, were there different points throughout where you thought you might have a movie and then you had to revise your plans when something new might be uncovered?

I knew I was going to cover that one Supreme Court case and I thought the story would be in there, but that case was summarily reversed. At the time, that could’ve been seen as a setback or a disappointment [since] it just shut down the storyline that I was following, but it was a good thing for the film in the long run because it drove me back to Montana to follow a much more nuanced story about the role of money in politics, especially the role of anonymous money in politics.

Were people in Montana eager to speak about it?

I think being from Montana really helped me get two degrees of separation from about anyone I wanted to talk to. I knew Steve Bullock, the attorney general at the time [of the Supreme Court case], because we went to the same high school, so I think that helped a little bit in establishing that rapport and that’s how I ended up following that case as it went to the Supreme Court. There’s not a lot of people there and I think the people who are from there tend to stick together, so I had much better access to folks because I was from there than I would’ve if I had just parachuted in and said, “I’m a documentary filmmaker from Brooklyn, talk to me.” So that regional approach, going back home to a place I really knew how the ropes worked, was a crucial part of having that access.

A scene from Kimberly Reed's "Dark Money"Growing up there, did you think it would be such fertile territory as a filmmaker?

Yeah, because I became a filmmaker there. [laughs] I’m just inspired by the beauty of Montana and I’m deeply inspired by the people. There’s such a wide variety of people there. This is not making documentaries in a blue bubble and I hope that what that has done is to give me a more empathetic approach to the folks that are sometimes written off by documentary filmmakers who come from the coasts. It’s important to talk about your own backyard and I think if you focus on the finest details in life, it gives you the world. Making these films about the place that I grew up gives me the world in a lot of ways, or at least it has for these last two films.

What’s it been like traveling with “Dark Money”?

I really hoped that the story wouldn’t get locked into Montana and be only a story about Montana [because] the ideas in this story are emblematic of the political gamesmanship that happens in every other state, so it has been be heartening to see our film being taken as an inspiring playbook for other states to follow. Whether we take it to Omaha or Nashville or Martha’s Vineyard to see it applied to politics on the ground, it shows me that the film is operating as planned and folks are able to apply this case study to their own particular political realities that they’re dealing with. It’s a tough issue to simplify and I’m glad it’s working.

“Dark Money” opens in Los Angeles on July 27th at the Nuart. A full list of theaters and dates is here.