WHAT the hell, Roseanne?

Riding high on a hugely successful reboot of her sitcom, Roseanne Barr's greatest asset - her big mouth - has become her downfall.

The series has been cancelled following bizarre, racist tweets from the star.

In a now deleted tweet, Barr compared former Barack Obama adviser Valerie Jarrett to an ape, saying it was like the "Muslim brotherhood & planet of the apes had a baby."

An equal opportunity offender, she also repeated false rumours that billionaire investor George Soros, who is Jewish and survived the holocaust, is a Nazi sympathiser and assisted the organisation during World War II​ (despite the fact he was 13 at the time).

Barr, 65, apologised "for making a bad joke" about Jarrett, who is black and was born in Iran to American parents.

But it was too little, too late. The ABC network was swift to act.

"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 cast of the Roseanne reboot, which has now been axed. (Pic: ABC)
The cast of the Roseanne reboot, which has now been axed. (Pic: ABC)

The decision wouldn't have been taken lightly. Roseanne was ABC's biggest hit of the 2017-18 season, pulling in a colossal 18 million viewers each week. In the brave new world of streaming, those are dream figures for a TV network. Only The Big Bang Theory, on CBS, had a bigger audience.

Her devastated colleagues, including Sara Gilbert, Wanda Sykes, Emma Kenney and Michael Fishman, have roundly condemned the tweets.

Sykes, a consulting producer and close personal friend of Barr, tweeted, "I will not be returning to @RoseanneOnABC".

Gilbert, who plays the acerbic Darlene, tweeted, "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."

What on earth was she thinking? It's easy to imagine that a wealthy star such as Barr is out of touch, except the wildly successful reboot of her series, which draws 18 million viewers in the US alone, proves the opposite. Politics, poverty and family, it's real and relatable, funny and smart. The Roseanne magic is all there, better than ever.

The set hasn't changed since the 90s. Darlene (Sara Gilbert) explains that's a decorating choice called 'poverty'. Roseanne and Dan (John Goodman) still struggle to pay the bills, even more so when their kids and grandkids return to Lanford, a fictional working class town in Illinois.

I watch a lot of telly in my role as a TV reviewer, and some good, some bad, some deadset shocking. In recent weeks, the Roseanne reboot had become a fast favourite.

Yesterday, I watched an episode which was scheduled to air here in two weeks, but is now won't see the light of day (Channel 10 released a statement on Wednesday saying they were "appalled and disgusted with Ms Barr's racist tweet," and confirmed the show had been pulled from channels TEN and ELEVEN "effective immediately").

In it, Roseanne is suspicious of her Muslim neighbour who has a huge amount of fertiliser.

She fears terrorism, but later realises her behaviour was ignorant and racist. It's a lot funnier than the retelling, but as always, the show delivers a lesson without lecturing.

Never afraid to play the bad guy, Barr is a Trump supporter both in real-life and in the series. It's left to her sister Jackie (Laurie Metcalf) - gullible, well meaning, left-leaning Jackie - to represent team Hillary, and in the storyline, the sisters fell out over their political differences.

Everything was going so well. So why did Barr do it? Maybe she had a few drinks too many and blew off steam on Twitter. She has also grappled with mental illness in the past. Is she depressed? Angry? Fortunately, she's not making excuses.

Yes, Barr has apologised, and is being punished. A great comedy series has been cancelled, and its cast, crew and fans are the ones who will miss out.