Filmmaker Michael Moore sounded the alarm for his fellow liberals Friday after news broke that Supreme Court Justice Ruth Bader Ginsburg had completed three weeks of treatment for a malignant tumor this summer.

“First thought:” Moore tweeted. “She was seen at the Yiddish version of 'Fiddler on the Roof' in NYC last week. She’s gonna be fine.”

Then he wrote, “Second thought: HOLYMOTHEROFRBG!!EVERYBODY, RIGHT THIS SECOND, JOIN A MOVEMENT, CAMPAIGN, GRASS ROOTS GROUP -WHATEVER - AND WORK NONSTOP BTWN RIGHT NOW & NOV 2020!”

RUTH BADER GINSBURG TREATED FOR MALIGNANT TUMOR ON PANCREAS, SUPREME COURT SAYS

Moore was apparently fearing that further health problems for Ginsburg could force the 86-year-old associate justice to step down from her lifetime appointment to the nation's highest court -- thereby presenting President Trump with a third opportunity to make a Supreme Court pick.

Trump has already placed conservative justices Neil Gorsuch and Brett Kavanaugh on the Supreme Court, following Senate confirmation for each. A third successful Trump appointee would likely bolster the court's conservative majority for decades to come.

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Moore appeared to be reminding liberals that electing a Democrat to the White House in 2020 would be the best defense against Trump making a third pick -- unless Ginsburg happens to step down before the 2020 election.

That appeared unlikely Friday. A court spokesperson said the tumor on Ginsburg’s pancreas was treated “definitively” and there were no other signs of cancer in her body.

Ginsburg has become a bit of a celebrity in the liberal community and Democrats watch the health of "Notorious RBG" very closely.

During a recent performance of “Fiddler on the Roof” in New York City, Ginsburg received a standing ovation.

Ginsburg underwent lung cancer surgery in December and has had two previous bouts with the disease. She had colorectal cancer in 1999 and pancreatic cancer in 2009. While recovering from surgery she missed arguments at the court in January, her first illness-related absence in more than 25 years as a justice.

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She joined the court in 1993 after being nominated by former President Clinton.