A potential Supreme Court vacancy in 2020 will turn into a “battle royal” if Senate Republicans flip the script and nominate a conservative judge during a presidential election year, pundits tell the Herald.

“Both sides would be fighting it out as if it’s Armageddon,” pollster John Zogby said Sunday. “Democrats would be saying, ‘This is the end of the world and the end of America as we know it.’ It would be a battle royal.”

Justice Ruth Bader Ginsburg, 86, who’s firmly seated on the left, appears to have survived another cancer scare. On Friday, it was announced doctors discovered a malignant tumor on her pancreas.

It was the second time Ginsburg, who had surgery to remove cancerous growths from her lung in December, has been treated for cancer in less than nine months.

Her health remains a constant concern for both liberals because the court is expected to shift right for decades if President Trump were to get the ability to nominate someone to replace her. The conservative court would have a 6-3 majority.

David Axelrod, who was senior adviser to President Barack Obama, tweeted: “If there is a SCOTUS vacancy next year and @senatemajldr carries through on his extraordinary promise to fill it — despite his own previous precedent in blocking Garland — it will tear this country apart.”

Obama nominated Merrick Garland to the Supreme Court in March 2016, but Senate Majority Leader Mitch McConnell blocked the Republican-led Senate from confirming a nominee, citing the pending election of a new president. The November election was supposed to be the deciding element, McConnell stated.

Pundits expect the GOP Senate would ignore its own 2016 precedent — thereby “enraging Democrats and many moderate independents,” said Larry Sabato of the Center for Politics at University of Virginia.

“The Democratic nominee for president is bound to use this to motivate the party base,” Sabato said of the possibility of a vacancy on the highest court.

There could also be unintended consequences from a 2020 appointment, he added.

“Some … may think it will lead to violence. I certainly hope not, but yes, it’s possible,” Sabato said.

Brad Marston, a conservative political consultant, said it would be smarter for Trump and McConnell to hold off on a nominee and instead focus on the election.

“If he nominates somebody, it’ll make what happened to (Supreme Court Justice Brett) Kavanaugh look collegial,” he said.

A nomination fight would also result in Democrats flooding the polls in November, Marston added.

But Ford O’Connell, a GOP national pundit, said a Supreme Court nomination battle could actually boost Trump in 2020.

“Because Republicans control both the Senate and White House, it’s well-within their right to appoint a new judge,” O’Connell said. “I really think it would help Trump more with enthusiasm from voters.”

Herald wire services contributed to this report.