“Captain America: Brave New World” is a mediocre-at-best movie, a roughly cobbled together film that pales in comparison to the early days of the Marvel Cinematic Universe. It’s still better than the franchise’s most recent run of disasters, and its strong opening weekend at the box office seems to have restored some momentum to the M.C.U.

But the most remarkable part of this film is the irony of how it lands in the political moment: “Brave New World” features a Black iteration of the quintessential American superhero a month into an administration that has made eliminating diversity, equity and inclusion one of its first priorities.

In a way, Disney’s timing regarding diversity was always going to be off. For most of the run of one of the highest-grossing media franchises of all time, diversity was an afterthought. For the first decade of the M.C.U., over the course of more than a dozen films, the heroes carrying the franchise — the central protagonists — were exclusively white men, until Chadwick Boseman led “Black Panther” in 2018.

So, yeah, Disney started out a little behind.

But when it came down to the handoff of the star-spangled shield from the blond-haired and blue-eyed Steve Rogers (played by Chris Evans) to Sam Wilson (Anthony Mackie), Disney actually built a steady platform for the M.C.U.’s first Black Captain America to lead his own film.

The 2021 Marvel TV series “The Falcon and the Winter Soldier” provided the space for Sam to develop into Captain America in earnest, not just as a kind of M.C.U. diversity hire.

Sam’s transformation into the Captain could have easily been the M.C.U.’s version of “The Blind Side,” a tale of a Black man’s triumph under the tutelage of the true, original white hero. He also could have been the Uncle Tom Captain, a servile Black man unquestioningly putting his life on the line.

But “The Falcon and the Winter Soldier” explored Sam’s reticence in taking on the mantle of Captain America, given how his Blackness so often marginalized him, made him a target or turned him into a stereotype in the eyes of some of his fellow citizens. The show also introduced a Black super soldier named Isaiah Bradley, who received the super serum like Steve Rogers. But Isaiah never became the lauded hero Steve did; he was made a prisoner and a science project, jailed and experimented on for 30 years. He’s a reminder to Sam of what can happen as a Black man in America, no matter his standing, his strength or his title.

This history and these racial issues don’t magically disappear when Sam gets his own film. Isaiah reappears in “Brave New World” to reinforce this point; he expresses his distrust of the government and warns Sam not to become a puppet for the president to use for his whims. In the movie, Isaiah is framed for an attack on the president, and a throng of police officers chase him across White House grounds and eventually imprison him. Isaiah is slated for execution. Yet again he serves as a reminder that even a Black superhero’s experience is still a Black man’s experience.

By the end of “Brave New World,” Sam has, of course, saved Isaiah, among many others, and proved his mettle in some flashy choreographed fight scenes (with and without his new-and-improved flight suit from the Wakandans). The film plays up his Captain as its own distinct hero, a Captain America with no super serum but better gear, a different temperament and a different style of fighting. (Some of the Captain’s signature flourishes, like the impressive shield-wielding, remain.) Along with Shuri’s transformation into the Black Panther in “Black Panther: Wakanda Forever,” Sam Wilson’s Captain America marks the official start of the next generation of Avengers, a lineup that will include more women and people of color.

It should be the time for such a diverse lineup of heroes, a Black Captain America included. In fact, it should have been the time decades ago. And yet the ultimate irony of Disney’s limited and delayed attempts at representation are that this film (originally slated for a May 2024 release) now lands at a time not only when the president is striking down diversity initiatives, but when many corporations are following suit. Disney is one that is following the trend, having just publicly rolled back some of its D.E.I. efforts.

Mackie’s Captain America has been met with predictable backlash from fans who think he isn’t worthy of the role. Though one weekend of receipts isn’t conclusive, it’s been apparent for the last several years that Marvel fans are ready for something new. And the best way for Disney to successfully usher fans through this next iteration is not by trying to predict which way the political winds will blow, but by providing well-written, fully developed characters of all backgrounds, with all the nuances and burdens and histories that come with them. This shouldn’t be too difficult or political an ask; Disney has shown itself capable, just not always willing.