Two days after the South Carolina primary in 2008, Ted and Caroline Kennedy endorsed Barack Obama after he beat Hillary Clinton there by 30 points. Obama spokesman Robert Gibbs said on Saturday that those Kennedy endorsements were extraordinarily important to the Obama campaign.

Think how much more crucial it would be right now if Obama finally followed suit and endorsed Joe Biden after his vice president’s smashing victory in the Palmetto State. There was a 10-day gap between Obama’s win in 2008 and the multistate primary on Super Tuesday.

This year, Super Tuesday is … this Tuesday. Biden could really use a massive news event to make the point to voters in those 14 states that he is a winner and a better choice against Donald Trump than Bernie Sanders — and Obama’s ego might be tickled by the prospect at being a decisive player in the race.

Former Democratic Sen. Claire McCaskill said she thought Obama would respect the process because he wouldn’t have liked it if someone had put his finger on the scale in 2008 while he was hunting for delegates? Yeah, I’m sure he really hated the Kennedy endorsements on his behalf.

The thing is, after Trump’s romp to the GOP nomination against the party establishment in 2016, the chattering classes have claimed endorsements no longer have any impact. That conventional wisdom was just proved wrong: Nearly a quarter of South Carolina primary voters said they were influenced in Biden’s direction by the endorsement this week of Rep. Jim Clyburn, the state’s most senior Democrat.

Multiply Clyburn by a thousand, and you could really see how Obama’s nod to Biden could represent a massive momentum shift.

The story of 2020 has been Bernie Sanders’ emergence as the seeming frontrunner — and the past week’s serious scrutiny of his long-held views shows he has no inclination to moderate opinions that make the left-liberal Obama seem like a neoconservative.

Is Obama going to stand by as his party takes the extremely risky step of nominating an open socialist when polls say nearly 60 percent of Americans have an unfavorable view of socialism and fewer than 30 percent say they view socialism favorably?

If he’s concerned about it, the only real opportunity Obama has to stop the Sanders march comes tomorrow or Monday. It’s fair to assume the former president has real concerns about the former vice president’s viability, but any possibility of another candidate emerging to challenge Sanders has all but evaporated.

Unchallenged, Michael Bloomberg’s money is just going to help Sanders by taking chunks of the non-Sanders vote. And what other effective challenge could there be to Scrooge McDuck and his swimming pool full of dollars than the most popular Democrat in the country anointing his preferred choice?

Unless, that is, Obama’s preferred choice is a brokered convention from which a surprise nominee emerges … named Michelle Obama.