When “Rustin,” a film about civil rights activist Bayard Rustin told with clarity and conviction, premiered a few weeks ago at the Telluride Film Festival, it received an enthusiastic reception, albeit on the polite side. Sure, for some, there was the thrill of discovering the life of a man mostly ignored in history books. But underlying that appreciation was a question: Couldn’t that tumultuous life have been conveyed with a little more messiness, a little less restraint?

“Rustin” may be a by-the-numbers biopic, but that’s because its makers (including, notably, the production company Higher Ground, founded by Barack and Michelle Obama) care most deeply about two numbers. The first is 250,000, the number of people estimated to have shown up at the March on Washington, the landmark 1963 demonstration where the Rev. Martin Luther King Jr. delivered his “I Have a Dream” speech. The second number is nine, the months that transpired between that peaceful protest and the passage of the 1964 Civil Rights Act. Those two events, the film argues, are inseparable.

Rustin spearheaded the Washington march and director George C. Wolfe (“Ma Rainey’s Black Bottom”) and screenwriters Julian Breece and Dustin Lance Black keep the film’s focus primarily on the nuts and bolts of the organizing, the negotiations and the compromises it took to put a couple hundred thousand “angelic troublemakers,” in Rustin’s words, on the National Mall. That approach means the movie is freighted with exposition, along with lengthy monologues and much stirring oration. For good and bad, “Rustin” seems destined to have a voluminous quotes page on IMDb. Sometimes, it goes with the territory.

If there’s going to be an abundance of talking (and talking at an abundant level of volume), it’s good to have Colman Domingo on your team playing the title character. When we’re introduced to Rustin, he’s a dynamo, sleeves rolled up, tie askew, eyes ablaze. If he’s in a room with King (played with quiet authority by Aml Ameen), Rustin is the one you’ll first notice. Rustin is also, as he explains as a way of foregrounding both his activism and individuality, born Black but “also born a homosexual.” He’s saying it out loud, which is notable given the time period and his standing.

Rustin was also a Quaker, a Communist (at least for a time), an accomplished singer and unknown to most Americans because, as an out gay man (or as out as he could be for the era), he could not be the star that, say, King was. The movie explores that marginalization — and Rustin’s conflicting feelings about it — to a degree. It also includes a romance between Rustin and a closeted, married preacher (Johnny Ramey). While that subplot ties together Rustin’s dual fights for acceptance, it feels inert and unconvincing. “Teach me how to not be afraid,” the clergyman, a composite figure of several acquaintances, asks Rustin, a line emblematic of the film’s occasional inelegance.

“Rustin” is on firmer footing when detailing the creative spit-balling that created the framework that made the March on Washington possible, as well as the competing egos and interests that almost doomed it. You’d need a 10-part limited series to really do all this justice, but the movie puts across the complexities with a nimble shorthand, employing the likes of Chris Rock (portraying NAACP leader Roy Wilkins, an initial antagonist) and Jeffrey Wright (as Rep. Adam Clayton Powell Jr., a consistent thorn) to command the screen. Of course, any time they share a scene with the charismatic Domingo, there’s only one place you’re going to look.

Rustin probably would have liked this movie, but not because it paints him as a hero, which it does, sometimes with a heavy hand. (Wolfe clearly admires him, filling the march with adoring faces gazing in his direction.) No, he’d probably like it because, in our current time where division can foster apathy and despair, “Rustin” is a movie about possibility. You want to change the world? Gather some like-minded souls, roll up your sleeves and dream. It might, this optimistic film posits, come true.