As Roseanne Barr unleashed a tweetstorm that included a racist post against Valerie Jarrett, who was a senior adviser to President Obama, Twitter was filled with impassioned responses, many coming from high-profile users. The conversation only grew louder once ABC announced it had fired Ms. Barr and canceled the next season of her sitcom, “Roseanne.” While some defended her, many condemned her words and applauded ABC for its decision.

When Ms. Barr likened Ms. Jarrett, who is black, to the offspring of “muslim brotherhood & planet of the apes,” several cast members of “Roseanne” distanced themselves from the statement and pledged to no longer work on the show.