Barr's tweet was a reply to a tweet that accused Jarrett of helping to cover up alleged misdeeds by the Obama administration.
Meanwhile, Obama's former national security adviser and ex-UN Ambassador Susan Rice noted that Barr called her "a man with big swinging ape balls" back in 2013 - retweeting a screengrab of the disgraced comedian's original tweet.
She played an avid Trump supporter in the rebooted ABC show as well and once told the Hollywood Reporter, "I think we would be so lucky if Trump won". Barr's Twitter account was still active as of noon ET on Tuesday.
Barr is notorious for tweeting about pro-Trump conspiracy theories and other controversial topics. A few hours after Barr's tweet, Wanda Sykes, a consulting producer on the Roseanne show, tweeted she will not be returning.More news: Aston Villa lose out on promotion to Premier League
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Some conspiracy theorists claim that Soros, the billionaire and left-leaning donor, was a Nazi collaborator or a member of the SS - a rumor that has been debunked. "That's not what the president's looking at", she said.
Barr later apologized for the tweet, saying it was a "bad joke" and saying that she would be leaving the social media platform. Our government is only going to be as good as we make it be. "Roseanne's recent comments about Valerie Jarrett, and so much more, are abhorrent and do not reflect the beliefs of our cast and crew or anyone associated with our show".
Ms. Dungey has encountered her share of difficulties - some involving diversity - since taking over as president of ABC Entertainment, a job that gives her oversight of prime-time and late-night programming, marketing and scheduling.
"This is incredibly sad and hard for all of us", she added, "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".