Frank Pallotta and Brian Stelter

(CNN Money) -- ABC canceled its hit sitcom "Roseanne" on Tuesday after the show's biggest star, Roseanne Barr, went on a racist Twitter rant.

"Roseanne's Twitter statement is abhorrent, repugnant and inconsistent with our values, and we have decided to cancel her show," ABC Entertainment president Channing Dungey said in a statement.

The cancellation was a shock in Hollywood. The revival of "Roseanne" premiered to huge ratings just three months ago.

Pre-production was already underway on a second season, which was scheduled for Tuesdays at 8 p.m. this fall.

When Barr's racist tweets caught fire early Tuesday, ABC went silent for several hours.

When asked why ABC ultimately decided to cancel the sitcom, a Disney source said, "It's a question of right and wrong. And it's a question of our company's values."

Reactions to the decision were overwhelming and largely positive.

"Some things apparently are more important than money," even for a network like ABC, "and that's heartening," CNN's Van Jones said on the air.

Earlier on Tuesday, Barr had apologized and said she was "now leaving Twitter."

But that wasn't enough for some of Barr's colleagues. One of the show's consulting producers, Wanda Sykes, said she's done with the show. "I will not be returning to @RoseanneOnABC," Sykes tweeted.

And Sara Gilbert, who plays Barr's daughter on the ABC sitcom, tweeted that Barr's comments are "abhorrent and do not reflect the beliefs of our cast and crew or anyone associated with our show."

Gilbert added: "This is incredibly sad and difficult for all of us, as we've created a show that we believe in, are proud of, and that audiences love — one that is separate and apart from the opinions and words of one cast member."

Barr is notorious for tweeting about pro-Trump conspiracy theories and other controversial topics. This week she repeatedly attacked prominent Democrats.

In one of the tweets, she wrote, "Muslim brotherhood & planet of the apes had a baby=vj."

Barr was responding to a comment about Valerie Jarrett, a top former aide to President Obama. She replied to CNN reporter Andrew Kaczynski and said it was "a joke."

But Barr later deleted the tweet and tweeted an apology to Jarrett and "all Americans."

"I am truly sorry for making a bad joke about her politics and her looks," Barr tweeted. "I should have known better. Forgive me -- my joke was in bad taste." Barr then said she's leaving Twitter.

Jarrett declined to comment.

Social media lit up with criticism of both Barr and ABC, with some demanding a response from the broadcast network. ABC has not replied to CNNMoney's request for comment.

In the past, ABC executives have privately said that they hold their noses when Barr tweets. They know some of her posts have been problematic -- full of pro-Trump conspiracy theories that mislead her fans. But not this time.

The executives want Barr to focus on her show. But they seem to take the position that there's no controlling Barr, and that's what makes her the successful comic she is.

ABC employees shared these views on condition of anonymity earlier this year, before the current Twitter controversy.

Barr also made comments on Twitter Tuesday about Chelsea Clinton, tweeting, "Chelsea Soros Clinton." She later replied in the comments that Clinton is "married to Soros nephew." Soros is a billionaire liberal benefactor who has been the subject to many right-wing conspiracy theories over the years.

Clinton responded to Barr shortly after.

"Good morning Roseanne - my given middle name is Victoria. I imagine George Soros's nephews are lovely people. I'm just not married to one," she wrote.

Barr responded back to Clinton saying, "Sorry to have tweeted incorrect info about you! Please forgive me!"

She then continued, "By the way, George Soros is a nazi who turned in his fellow Jews 2 be murdered in German concentration camps & stole their wealth-were you aware of that? But, we all make mistakes, right Chelsea?"

This is a conspiracy theory about Soros that has been debunked many times. The fact-checking site Snopes called it "false" back in 2016.

Barr's followers are accustomed to her conspiratorial tweets, but even by her standards, Tuesday was outrageous.

Some commenters connected her behavior to Trump-era intolerance and said ABC was helping to normalize racism by supporting her show.

MSNBC's "Morning Joe" host Joe Scarborough was critical of ABC on Twitter.

"Hey @ABC, Roseanne Barr compared Valerie Jarrett to an ape. There is no apology she can make that justifies @ABC turning a blind eye to this bigotry by airing another second of her show," he tweeted. "Even in the Age of Trump, there are red lines that can never be crossed. This is one."

Others like civil rights activist DeRay Mckesson called on the network to cancel the show earlier on Tuesday.

".@ABC, how desperate are you to profit from Roseanne's racism? We know racism sells in this country, it always has. But you don't have to participate in it," he tweeted. "This apology is meaningless. Cancel Roseanne."

The premiere of Roseanne's reboot was one of the highest-rated new shows of the season, and Barr is one of the network's biggest stars, if not its biggest.

However, after the huge debut, which brought in more than 18 million live viewers, the show saw its audience come back down to earth. Its finale, which aired last week, nabbed roughly 10 million viewers.

The viewership was so big that even President Trump praised the debut of the show saying, "Over 18 million people! And it was about us!" The President also called Barr after the premiere to congratulate her.