Roseanne Barr, arguably the face of “pro-Trump” Hollywood, has seen a recent career boost built on giving a voice to the millions of Americans who support the president. But a Tuesday morning Twitter rant that led to network executives canceling her show did that group more harm than good.

Barr invoked racist and Islamophobic stereotypes that triggered so much outrage that ABC canceled her successful sitcom. The most offensive tweet has been deleted, one combining a common anti-black racist trope with a conspiracy theory referring to former Obama White House senior aide Valerie Jarrett.

She also retweeted pieces accusing Jarrett’s mother of being a communist, among dozens of other retweets Tuesday. Other topics included falsely claiming that Chelsea Clinton was related by marriage to billionaire liberal activist George Soros, prompting a brief back-and-forth with Clinton, capped by Barr’s sharing of a false but widespread conspiracy theory about Soros.

Roseanne Conner, the lead character in the ABC sitcom that became a megahit in its first revival season this year, is a different person from Roseanne Barr. The actress and her fictional persona live in different parts of the country, have different family structures and different net worths.

But their politics have some similarities, making it easy for viewers to conflate the two. And Barr often points to her working-class roots growing up in a red state as being pivotal in her…