In 2014, Billboard launched the “Fan Army Face-Off,” a bracket-style online vote that pitted pop stars’ fans against one another. The crowd-sourcing exercise was not exactly original, but its language—which set fan bases up in imaginary battles—encapsulated the increasingly combative state of pop-music fandom. Some fan-group monikers have become household names: Beyoncé has the Beyhive, Justin Bieber has Beliebers, Rihanna has a Navy, Selena Gomez has Selenators, Taylor Swift has Swifties. Unlike, say, the way Deadheads followed their band from city to city, this modern style of adoration takes place chiefly online, where it is driven not only by jubilation but by fierce defensiveness. Followers pounce on anyone—big, small, notorious, anonymous—who criticizes their idols. There is a dark, obsessive energy to such devotion; fittingly, these crusaders are now often referred to as “stans”—a reference to a song by Eminem, from 2000, which tells the story of a fictional fan named Stan who writes increasingly unhinged letters to the rapper before driving his car into a river.

Few groups embody the culture of music fandom better than the Barbz, or the Barbies, the fans of Nicki Minaj, whom she named herself, a decade ago, when she was a sparkling newcomer in a hip-hop landscape with a notable lack of female stars. As she grew in stature, so did the Barbz, who launched robust fan accounts on social-media platforms to cheer her on and to document her success. Minaj went on to become the most celebrated female rapper of her generation. And she encouraged her fans, retweeting them, messaging them, joking around with them, and surveying them about their desires and preferences. In time, however, the fans’ giddy engagement morphed into fury levelled at the growing number of online commenters—other artists and their fans, critics, radio d.j.s, and civilians on Twitter—who criticized Minaj. The Barbz also grew paranoid—both Minaj and her followers have accused her detractors, as well as cheerleaders of other artists, of accepting payola in an attempt to ruin her career.

While many popular musicians have stepped away from social media—cultivating a strategic distance—Minaj has leaned into it, often to her detriment. She has sent her fans to do her bidding, and then reeled them back in when she needed to. Cocooned by unconditional loyalty, she recently began behaving as if she were one of the Barbz herself, rather than their leader. When a twenty-six-year-old writer, Wanna Thompson, a self-described Minaj fan, tweeted her wish that Minaj would abandon the “silly shit” in her music in favor of “mature content,” the rapper sent Thompson a private message calling her “ugly” and “jealous,” which Thompson posted publicly. Some of Minaj’s devotees flooded Thompson’s social-media accounts with insults and death wishes.

This fan-artist dynamic represents an odd inversion of the conventional distribution of power between a famous person and the people who follow her. “It’s like a lion with their cubs,” one Barb told Rolling Stone. “A female lion with her cubs, you don’t mess with the babies, and Nicki is our baby.”

If Minaj is that fragile, she does not explore this quality explicitly in her music. Earlier this month, she released her latest studio album, “Queen.” In her lyrics, Minaj positions herself as being as dominant as ever in her career, if a bit tortured in her romantic life. She guards her throne intensely, though not always convincingly. Her default mode is chest-beating, and she raps constantly about her reign as though it will last forever, no matter how many young female insurgents aim to replace her. “They’ll never toe to toe on a track with me / There’ll never be another one after me / ’Cause the skill level still just a half of me,” she raps on “LLC,” a hard-spitting song on which she plays her familiar trick of beginning a verse at a slow, measured pace before suddenly shifting into double time to drive her point home.

Anyone who has caught one of Minaj’s many guest verses on various prominent rap songs of the past decade will be able to anticipate this technique. Early in her career, Minaj made waves with her elastic vocal capabilities, inhabiting a range of styles. Following her guest verse on Kanye West’s “Monster,” in which she effortlessly alternated between the impish and the demonic, she was widely considered hip-hop’s most exciting new vocalist. Her range made her palatable on many kinds of songs: trap rap, bubblegum pop, and moody, melodic R. & B. It has been nearly four years since her previous album, “The Pinkprint,” but “Queen” does not reflect the passage of time. It uses the same template as her first three albums—a lengthy, base-covering mix of gymnastic, barbed rap verses and introspective lite pop, studded with playful winks and of-the-moment appearances by collaborators.

History-making stars often fixate on the momentousness of their rise, which has the effect of paralyzing them in a backward-looking gaze. Minaj has fallen into this hole hard, perhaps because it connects to the self-mythologizing and braggadocio that have characterized so much of New York hip-hop. It feels cheap to draw a parallel between Minaj and President Trump, but the attitudinal similarities—the obsession with winning, the instinct to dismiss critics as losers or liars, the paranoia, the rabid fixation on the initial victory rather than the ensuing work—are also too obvious to ignore.

Minaj’s stylistic modes attract two sets of followers: more traditional hip-hop fans and younger, more pop-leaning ones. Minaj’s music, since her early days of stardom, has reflected the difficulty of this tightrope walk. The Barbz may be offering her support—both psychological and financial—but they also insulate her from reality, influencing her process the way that critics cannot. Minaj may never be able to envisage a path that sidesteps these musical categories altogether unless she tunes out the warring factions and turns inward.

Last year, the radio host Charlamagne Tha God criticized Minaj for failing to respond in a timely fashion to a withering seven-minute diss track from her fellow New York rapper Remy Ma: “Maybe this is your way of saying ‘You know what? I don’t want to rap anymore. I like this pop world. I’ma do songs with Ariana Grande for the rest of my life and call it a day.’ ” Ariana Grande, the twenty-five-year-old former Nickelodeon star and pop-vocal powerhouse, has become something of a cudgel for Minaj. The pair first collaborated in 2014, on a chintzy Jessie J pop anthem called “Bang Bang,” at the height of the battle between Minaj’s hip-hop and pop sides. At the time, rap-radio d.j.s accused her of betraying her hip-hop roots with youth-friendly starlets like Grande. (There is, of course, a gendered aspect to these criticisms, not only because Minaj is one of the few prominent female rappers but because the pop-leaning fans are often young women.) Grande and Minaj have since formed an alliance that feels as strategic as it is artistic, using each other as a bridge to another audience.

Grande, a seasoned singer with a theatre background, is trying to move from the teen-friendly bubblegum R. & B. of her early career to a smoldering, hip-hop-influenced pop. Grande and Minaj have collaborated on five songs, resulting in the merger of two hot-blooded fan bases. (Grande lovers are dubbed, awkwardly, the Arianators.) Grande released her new album, “Sweetener,” a week after Minaj put out “Queen.” “Sweetener,” in part a response to the suicide bombing at Grande’s show in Manchester, England, last year, is more understated than her previous work, less reliant on anthemic choruses and her expansive vocal range. Grande and Minaj appear together on both “Queen” and “Sweetener,” and the evolution of their relationship is stark: Minaj once spiked Grande’s girlish work with a risqué energy. Now Grande tempers Minaj’s songs with a more serious sound.