Every controversial step that led toward ABC's 'Roseanne' cancellation - from Pizzagate to Parkland to the final racist last straw

Barr's Twitter history was layered with conspiracy theories such as Pizzagate until she deleted much of her Twitter last year. "Pizzagate" was a conspiracy that claimed that Hillary Clinton's campaign was using a Washington, D.C. pizzeria as a front for a child trafficking ring, which prompted a man to open fire in a crowded pizzeria in December. Barr has also promoted the conspiracy that the death of Democratic National Convention staffer Seth Rich was a DNC cover-up.

In March, just before the "Roseanne" premiere, Barr replied "NAZI SALUTE" to a tweet that tagged Hogg. The tweet was deleted shortly after, but it appeared to be in response to a far-right conspiracy that Hogg raised a Nazi salute at a March for Our Lives rally.

"Roseanne" co-showrunner Bruce Helford defended the show, and told The Hollywood Reporter in April that "Nobody is making anybody watch the show."

"There should be an understanding that there is a difference between people's personal politics and what you present onscreen," Helford said. "We're hopefully presenting a wonderful, balanced show that doesn't have an agenda."

He added: "We consider ourselves guests in the public's home and as guests we know that people have the option to turn it off if they don't want to watch."

On one episode, Roseanne and her husband Dan (played by John Goodman) wake up from a nap with the TV on.

Roseanne says, "We slept from 'Wheel' to 'Kimmel.'"

"We missed all the shows about black and Asian families," Dan says.

"They're just like us," Roseanne replies.

This exchange was in reference to ABC's minority-led comedies "Fresh Off the Boat" and "Black-ish." This caused a stir on Twitter, as many didn't appreciate the idea that the show was trying to compare white, working-class Trump supporters to minorities who are rarely seen on TV.

Hellford responded to this controversy, as well: "We were commenting on the fact that all sitcoms really want everybody to feel included of all diversities and it's kind of a funny thing."

The episode finds Roseanne spying on her Muslim neighbors because she is suspicious of them, and makes numerous racially insensitive jokes. Muslim-American writer Elham Khatami said, "Roseanne thinking her Muslim neighbors are terrorists isn't funny. Not even for a second. Muslims deal with that bigotry on a daily basis. And it's dangerous."

Barr defended the episode by tweeting that she likes "to do TV episodes about REAL ISSUES & REAL PEOPLE."

At the beginning of this month, "Roseanne" fell behind CBS' "NCIS" for the first time. But its numbers still held strong. It had the most viewers of any scripted show this year so far, according to Nielsen.

Barr tweeted on Tuesday "muslim brotherhood & planet of the apes had a baby=vj" in response to a tweet that accused Valerie Jarrett of hiding illegal acts from the Obama White House. Jarrett, a black woman born in Iran, was a senior adviser to former President Barack Obama.

Hours after the tweet, ABC announced it was canceling "Roseanne."

"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.

Barr's agency, ICM Partners, also dropped her on Tuesday.

"Everyone took a good hard look at the success of Roseanne," Fox TV group CEO Dana Walden told Deadline. “It reminded us we have a huge iconic star in our Fox family in Tim Allen. And we have been talking to Tim through the year."

The ratings success of "Roseanne" emboldened Fox to revive "Last Man Standing," as Allen is a notable conservative. He doesn't, however, have Barr's history of controversial statements.