Riseborough was unexpectedly nominated for her performance as an alcoholic Texas single mother in the scantly seen indie drama “To Leslie,” a pick that shocked Oscar pundits and has since brought scrutiny from the Academy of Motion Pictures Arts and Sciences. For a movie that has grossed $27,322 at the box office, “To Leslie” and Riseborough have made a lot of noise.

At issue is the way Riseborough’s candidacy was promoted. Though many awards contenders are backed by orchestrated campaigns paid for by their film’s studio, Riseborough rose into the Oscar ranks thanks largely to the grassroots efforts of “To Leslie” director Michael Morris and his wife, actor Mary McCormack. They urged stars to see the film and either host a screening or praise Riseborough’s performance on social media. And a whole lot of them did.

So what’s the big deal? Cronyism in Hollywood isn’t exactly news; it’s more or less the modus operandi. But Riseborough’s nomination — and the strong response it’s engendered — has disrupted this year’s Oscar season, with potential repercussions for the Academy Awards in March and the bids of all future Oscar hopefuls.

Who is Andrea Riseborough?

For about 15 years, the 41-year-old Riseborough has been a regular presence in film, television and London theater, but she’s sometimes hard to register because of her chameleonic performances. She appeared in Mike Leigh’s “Happy-Go-Lucky” (2008). She made an impression as Riggan’s girlfriend in “Birdman” (2014). She played Stalin’s daughter in “The Death of Stalin” (2017). In “Mandy” (2018), alongside Nicolas Cage, she played his character’s kidnapped girlfriend. Riseborough had several other notable credits in 2022, including David O. Russell’s “Amsterdam” and as Mrs. Wormwood in “Matilda the Musical.” She’s been doing acclaimed work in adventurous independent film for long enough that an Oscar vote for her may have also been partly for her unassuming body of work.

How unexpected was Riseborough’s nomination?

Almost no one expected Riseborough’s late-breaking campaign to actually land her a nomination. It wasn’t totally out of left field, though. Riseborough’s performance in “To Leslie” had been nominated for an Independent Spirit Award. But she wasn’t expected to be in the mix in what was generally considered the hardest category to break into this year. Riseborough was nominated along with Cate Blachett (“Tár”), Michelle Williams (“The Fabelmans”), Ana de Armas (“Blonde”) and Michelle Yeoh (“Everything Everywhere All at Once”).

“I’m astounded,” Riseborough told Deadline shortly after the nominations were announced. “It was so hard to believe it might ever happen because we really hadn’t been in the running for anything else. Even though we had a lot of support, the idea it might actually happen seemed so far away.”

Two highly regarded performances were left out: Viola Davis in “The Woman King” and Danielle Deadwyler in “Till.” That the category’s most glaring snubs were both Black women has been a point of discussion. “Till” director Chinonye Chukwu, in a post on Instagram, suggested the system had failed. “We live in a world and work in industries that are so aggressively committed to upholding whiteness and perpetuating an unabashed misogyny towards Black women.”

What made Riseborough’s campaign different?

Most every acting nominee participates in some kind of Oscar campaign to help highlight their performance and get voters to watch their film. It’s a game that’s played. The playwright and screenwriter Jeremy O. Harris noted on Twitter: “Do people not realize that what the actresses did for Andrea Riseborough happens in private every night for months starting in October for every movie/performance (with) a chance.”

There are rules that limit the kinds of events that are held and even how much someone can email promotions to academy members during the voting period. Most campaigns have veteran strategists behind them and a substantial amount of money. Those pushing Riseborough, though, managed to draw attention to her without such backing. Instead, they counted on A-listers to spread the word.

Kate Winslet, Charlize Theron, Jennifer Aniston, Gwyneth Paltrow, Amy Adams and Courteney Cox all hosted screenings for the film. “You should be winning everything,” Winslet told her in a virtual Q&A. Other stars like Edward Norton, Susan Sarandon, Mira Sorvino and Rosie O’Donnell added their praise for her on social media. Those who supported Riseborough saw in the campaign — no billboards on Sunset, no “For Your Consideration” ads, just a deep Rolodex — a groundbreaking way to circumvent traditional Oscar rituals. In a since-deleted post, actress Christina Ricci wrote of the backlash to Riseborough’s nomination: “So it’s only the films and actors that can afford the campaigns that deserve recognition? Feels elitist and exclusive and frankly very backward to me.”

Did that break any rules?

There is no public evidence that Riseborough or anyone on her behalf clearly broke academy regulations. The screenings and endorsements that propelled Riseborough are commonplace. Some have speculated that Riseborough may have received a boost because of the strong passion of her supporters, who might have made her their top nominee.

But if the academy found that anyone violated the rules about contacting academy members “directly and in a manner outside of the scope of these rules,” the academy’s board of governors “may take any corrective actions or assess any penalties, including disqualification,” according to academy bylaws. “Furthermore, any academy member who has authorized, executed or otherwise enabled a campaign activity that is determined by the board of governors to have undermined the letter or spirit of these regulations may be subject to suspension of membership or expulsion from the academy.”

Oscar nominations have rarely been rescinded but it has happened. In 2014, composer Bruce Broughton, nominated for best original song, was disqualified after it was revealed he had emailed music branch members to call attention to the song’s submission. At the time, Broughton, a former governor for the academy, was a member of the music branch’s executive committee.

How has the Academy responded?

The academy has not commented on Riseborough’s nomination. But on Friday, it announced that it will conduct a review of the campaign procedures arounds this year’s nominees “to ensure that no guidelines were violated, and to inform us whether changes to the guidelines may be needed in a new era of social media and digital communication.”

“We have confidence in the integrity of our nomination and voting procedures, and support genuine grassroots campaigns for outstanding performances,” the academy added.