‘Roseanne’ Canceled by ABC Hours After Racist Tweet by Roseanne Barr

ABC canceled the hit sitcom “Roseanne” on Tuesday hours after the show’s star and co-creator, Roseanne Barr, posted a racist tweet about a former top adviser to President Barack Obama.

Early on Tuesday, Ms. Barr posted a comment about Valerie Jarrett, an African-American woman who was a senior adviser to Mr. Obama throughout his presidency and considered one of his most influential aides, that said if “muslim brotherhood & planet of the apes had a baby=vj.”

Hours later, ABC canceled Ms. Barr’s show, which had ended its successful comeback season last week and was expected to return in the fall for 13 episodes.

“Roseanne’s Twitter statement is abhorrent, repugnant and inconsistent with our values, and we have decided to cancel her show,” ABC’s entertainment president, Channing Dungey, said in a statement. Ms. Dungey was appointed to her current role in February 2016, becoming the first black entertainment president of a major broadcast television network.

Robert A. Iger, the chief executive of the Walt Disney Company, ABC’s corporate parent, shared Ms. Dungey’s statement on his own Twitter account, adding: “There was only one thing to do here, and that was the right thing.”

The sudden cancellation of a hit show with some of the highest ratings for a new series in years stunned an industry in which high ratings have become increasingly elusive.

The move’s swiftness was decided by Ms. Dungey with the support of Mr. Iger, who was involved in the process starting very early on Tuesday, according to two Disney insiders who spoke on the condition of anonymity to describe company matters.

There was more at stake than just a hit show. Disney has been widely praised in recent years as a leader in efforts to combat racial stereotypes through its movies and TV series, whether on “Doc McStuffins,” a Disney Channel cartoon about an African-American girl who wants to be a doctor; “How to Get Away With Murder,” a vehicle for Viola Davis to become the first black woman to win a lead-actress Emmy; and “Black Panther,” which smashed an entertainment-industry belief that movies rooted in black culture could not become global blockbusters.

If Disney did not act forcefully with regard to “Roseanne,” much of that work might have been rendered moot.

Although the second season of “Roseanne” was not scheduled to air for four months, the timing of Ms. Barr’s racist post was terrible for ABC. She wrote the message just two weeks after the network made its pitch to advertisers about its coming fall lineup, with the hope of attracting up to $9 billion in advertising commitments by summer’s end. “Roseanne,” and its enormous audience and broad appeal, was the centerpiece of ABC’s presentation. Ms. Barr was introduced to the stage at Lincoln Center’s David Geffen Hall before any other ABC executive or star.

Ms. Barr’s Twitter account was also the source of some lighthearted humor during the network’s presentation. She joked that her tweets were actually written by the head of ABC’s television group, Ben Sherwood.

When he followed her on stage, Mr. Sherwood joked that he had “absolutely nothing to do with Roseanne’s Twitter account,” while displaying a parody tweet by Ms. Barr that referred to him as more “handsome” and “rugged” than Ben Affleck.

Then came Ms. Barr’s tweet about Ms. Jarrett.

Ms. Barr initially dismissed accusations that the comment was racist, defending it as “a joke.” She also said on Twitter, “ISLAM is not a RACE, lefties. Islam includes EVERY RACE of people.”

She later deleted the post about Ms. Jarrett, and initially said nothing about the reference to “The Planet of the Apes.” About a half-hour later, she offered an apology.

“I apologize to Valerie Jarrett and to all Americans,” she wrote. “I am truly sorry for making a bad joke about her politics and her looks. I should have known better. Forgive me – my joke was in bad taste.”

Ms. Barr also said she was “leaving Twitter.”

The fallout over the Twitter post had begun earlier. Wanda Sykes, the black comedian who served as a consulting producer on “Roseanne” this season, said she was leaving the sitcom. Whitney Cummings — a showrunner for the revived comedy, and one of its most outspoken liberal supporters — had already left the series this month.

The Rev. Al Sharpton said that Ms. Barr’s comparing Ms. Jarrett to an“APE is racist and inexcusable. ABC must take action NOW!” Tom Arnold, Ms. Barr’s former husband and co-star, called her Twitter posts “dangerous.” And the MSNBC host Joe Scarborough said, “There is no apology she can make that justifies @ABC turning a blind eye to this bigotry by airing another second of her show.”

Before she apologized, Ms. Barr had an exchange with Chelsea Clinton after Ms. Barr referred to Ms. Clinton as “Chelsea Soros Clinton,” a reference to George Soros, the billionaire liberal donor who is often the focus of conservative critics. Donald Trump Jr. shared one of Ms. Barr’s posts in the exchange.

Ms. Barr’s often incendiary use of Twitter has stayed in the background amid the “Roseanne” revival’s success.

Months before the show premiered, she said that her children had taken her social media accounts away from her. It was no small matter: Ms. Barr has used Twitter to promote conspiracy theories, and some ABC executives were worried that she might say something offensive enough to lead viewers or advertisers to revolt.

Ms. Barr has been outspoken in her support of President Trump, who called to congratulate her on the ratings for the show’s premiere episode, and in her antipathy toward Hillary Clinton.

[Read an interview with Ms. Barr, in which she touches on her and her character’s support of President Trump.]

But as viewers flocked to “Roseanne,” to the delight of ABC executives, Ms. Barr returned to Twitter. None of her posts threatened the show’s success, although some did attract scrutiny. One of Ms. Barr’s messages accused a survivor of the high school shooting in Parkland, Fla., of giving a Nazi salute; another involved a conspiracy theory about Mr. Trump quietly breaking up a child sex trafficking ring including prominent Democrats.

ABC was able to sidestep controversy in both instances.

“You can’t control Roseanne Barr,” Mr. Sherwood, the president of ABC’s television group, said in an interview with The New York Times in March, when asked about her Twitter account. “Many who have tried have failed. She’s the one and only.”

There have been other sources of controversy.

The revival’s third episode featured a joke about two ABC comedies with diverse casts, “black-ish” and “Fresh Off the Boat.” Ms. Barr’s character and her husband, Dan, played by John Goodman, wake up on the their living room couch, having fallen asleep in front of the television. “We missed all the shows about black and Asian families,” Dan Conner said. To laughter from the show’s studio audience, Roseanne Conner responded, “They’re just like us. There, now you’re all caught up.”

The joke prompted an outcry but ABC defended the show. “We felt writers were looking to tip a hat to those shows,” Ms. Dungey said this month. “It certainly wasn’t meant to offend. I do stand by the ‘Roseanne’ writers.”

Even as the “Roseanne” revival experienced success, ABC’s relationship with the “black-ish” showrunner, Kenya Barris, deteriorated. The network made the rare decision earlier this year to pull an episode of the show, which is known for its frank assessment of race relations. The episode involved the main character, Dre, raising socially fraught issues while telling a bedtime story to his son. Mr. Barris is in negotiations to leave his ABC contract and begin working with Netflix.

“Roseanne” will probably finish the 2017-18 television season as the No. 3 rated show, behind two NBC programs: “Sunday Night Football” and “This is Us.” More than 18 million people on average have watched “Roseanne” this season, according to Nielsen’s delayed viewing data.

[The “Roseanne” revival suggested that “as long as you’re good to your neighbors individually, it doesn’t matter how you treat people in the aggregate,” wrote our critic.]

Still, the series was an afterthought on the Walt Disney Company’s most recent earnings call with investors. Despite its outsize success, “Roseanne” was not mentioned in the company’s prepared remarks, and it was only referenced after an investor asked a question about how the company felt about the network’s position going into a new TV season.