The odds of President Biden giving up his 2024 re-election campaign have soared to more than 80% — as the once-defiant Democrat is said to be “soul-searching” about dropping out of the race.

The likelihood that the 81-year-old president drops out was at 84% and rising as of early Friday, according to predictive betting website Polymarket.

Those odds skyrocketed after his train-wreck June 27 debate against former President Donald Trump, when the odds had hit a low of 19%.

Since then, Biden has faced increasing pressure — both publicly and behind closed doors — from heavyweights within his own party to cede his position at the top of the ticket.

The defiant commander-in-chief has so far been adamant that he will remain in the race for the White House. “I am all in,” he vowed as recently as Wednesday, the day he was confirmed to have COVID.

Privately, though, speculation has been rife that he is taking the calls to step aside seriously, and multiple Democratic officials think an exit is only a matter of time, multiple sources told Reuters.

“His soul-searching is actually happening, I know that for a fact,” one source said. “He’s thinking about this very seriously.”

Another source, who is a Democratic congressional aide, said the writing appeared to be on the wall for Biden after top Dems including Senate Majority Leader Chuck Schumer (D-NY) and former House Speaker Nancy Pelosi (D-Calif.) reportedly urged him this week to drop out of the race.

“It feels like it’s a matter of … when, not if,” the aide said.

“Yes, it’s over. Just a matter of time,” added another source, a Biden campaign official.

A Biden campaign spokesperson, however, rejected suggestions that he is ready to step aside.

“He is not wavering on anything. The president has made his decision,” deputy campaign manager Quentin Fulks said. “Joe Biden has said he is running for president of the United States. Our campaign is moving forward.”

With Post wires