From left, Sam Rockwell, Babou Ceesay and Taraji P. Henson star in "The Best of Enemies." (Annette Brown/STX Films)

Jonathan Wilson-Hartgrove directs the Ann Atwater Freedom Library in Durham, N.C.

As presidential campaigns begin to test unifying messages for 2020, they might find inspiration in a little-known story of interracial coalition-building arriving in movie theaters this spring. I know the story of “The Best of Enemies” because, as a young white man from the South, I was adopted into the freedom movement by Ann Atwater, the African American community organizer whose vision for fusion politics is its driving force. Because I knew Grandma Ann and the beloved community she welcomed me into, I know that true multiethnic democracy is possible. In the midst of the identity crisis we face as a nation, the organizing tradition that Atwater embodied is the strong medicine we need: It has the potential to break through the lie that has convinced us that for one community to win, another must lose.

“The Best of Enemies” tells the unlikely story of how Atwater (played by Taraji P. Henson) came to work with C.P. Ellis (Sam Rockwell), a local leader of the Ku Klux Klan, to develop a plan for school desegregation in Durham, N.C. Atwater and Ellis had spent years rallying their competing bases to out-shout each other in public debates over civil rights. But in 1971, when the AFL-CIO received a federal grant to help Durham comply with the 1954 Brown decision that had outlawed segregation in public schools, Atwater and Ellis each agreed to co-chair the process in order to keep the other from controlling the outcome. In the process of working together, they discovered something neither of them had really understood before: They were both poor, and a system that kept them poor was their common enemy.

When I met Atwater three decades later, I asked whether she would teach me what she had learned about community organizing. “Well, it’s pretty simple,” she said. “I listen to you until I learn what you want, then I help you get it. When we get halfway to what you want, I’ll tell you what I want.” Atwater’s fusion organizing philosophy makes her story — and that of “The Best of Enemies” — different from much-derided movies such as “Green Book,” in which dignified black people raise the consciousness of white people who remain at the center of the story. When genuine fusion organizing works, everyone benefits and everyone changes.

Atwater first learned community organizing from Howard Fuller, a charismatic young man who showed up at her door in the mid-1960s, when she was living in dilapidated housing in Durham’s segregated Hayti community. Atwater wanted basic repairs to the house she was renting, and Fuller helped her get them. Then he told Atwater he wanted her to attend a 17-week community action technician training. She emerged from the program with a clear understanding of how she could help others who faced the same challenges she did. She organized neighborhood councils in all of segregated Durham’s African American communities to demand equal access to government services and economic opportunity. Durham’s lunch counters were long since integrated, but Atwater knew all too well that she couldn’t afford to eat at them.

Though he wasn’t about to confess his need to her, Atwater knew that Ellis couldn’t afford to eat out downtown either. The son of a millworker from East Durham, Ellis had grown up in poverty and struggled to keep his family afloat running a small gas station in a factory town where the bosses made their fortunes from the labor of poor black and white people. Ellis had joined the Klan as a young man and took pride in his white identity. Truth be told, he didn’t have much else to take pride in. He wanted his children to get a good education and have a better life than him. A good organizer, Atwater knew that if she could help him get that, she could tell him what she wanted: a community where his kids and hers could share equal opportunity and a better future together.

This partnership has radical implications. It offers a concrete vision of the coalitions that are possible when people who have been pitted against one another by systemic racism do the hard work of laboring together long enough to discover that we want the same things: a good education for our kids, a living wage for our work, equal access to what we all need to thrive. Atwater and Ellis didn’t just become friends; they also worked together to fight poverty and systemic racism for the rest of their lives. Ellis died first, in 2005. Atwater delivered his eulogy.

As Americans struggle to find our way forward together, “The Best of Enemies” offers a hopeful vision from our past. If a civil rights leader and a Klansman could forge a friendship for systemic change, then poor and marginalized people who have been pitted against one another because of race, immigration status, gender and sexuality can work together to build fusion coalitions that transform broken systems today. Atwater taught me that multiethnic democracy is not only possible; it’s also a necessity. Either we learn to live together as family, or we will destroy one another in a battle that only serves to empower those who profit from our divisions.