President Joe Biden spurned former President Barack Obama’s calls in the two weeks before Biden dropped his re-election bid last July — and then wouldn’t speak to his ex-boss for another month, according to a new book on last year’s race for the White House.

Biden, now 82, served eight years as vice president to Obama, now 64, but their relationship soured as the first black president’s hand was rumored to be behind a devastating George Clooney New York Times op-ed, published July 10, 2024, that called on Biden to step aside following his disastrous June 27 debate with former President Donald Trump.

The Oscar-winning actor had declared in the scathing piece that Biden “cannot win” less than a month after co-hosting a fundraiser that brought in some $30 million for the Democratic ticket, but was overshadowed by Biden freezing up during the event and having to be led offstage by Obama.

“Obama had been trying to get in touch with Biden for about two weeks, but his calls had not been returned,” ABC News chief Washington correspondent Jonathan Karl writes in an excerpt from his upcoming book “Retribution: Donald Trump and the Campaign That Changed America” that was published by the Dispatch on Friday and detailed the 48 hours before Biden announced he was leaving the race.

“Obama reached out again after Biden suspended his campaign, but the two men would not end up speaking until shortly before the Democratic National Convention four weeks later.”

A Biden spokesperson declined to comment, and an Obama rep did not immediately respond to a request for comment.

Biden’s feelings toward Obama were complicated throughout his own term by the fact that the charismatic 44th president’s star power dwarfed Biden’s own, something that was felt whenever Obama dropped by the executive mansion.

“Obama caused tension when he would visit the White House because he operated as if he still ran it,” a Biden White House official told The Post.

“He made Biden feel secondary in the room even when staffers were present.”

A prominent Democratic source familiar with the dynamics said, “Joe Biden might forget a lot of things these days, but one thing he will always remember is that President Obama was a morning glory friend to him rather than in constant bloom.”

“The lesson here is one for us all: find friends who are for you 100% of the time,” the Democrat said.

“That wasn’t Obama to Biden, and it’s certainly not what happens in politics. Joe Biden deciding to ignore Obama showed him taking some modicum of his dignity back. Pretty relatable for many people.”

According to Karl, Biden also refused to take calls from former House Speaker Nancy Pelosi (D-Calif.), who was leading efforts by congressional Democrats to push him out of the race.

The excerpt describes Biden as relying mostly on his inner circle of advisers and immediate family members in the period before he ended his candidacy due to bleak polling data and an ever-growing list of elected Democrats calling for him to bow out.

Vice President Kamala Harris declined to call members of Congress to urge them to stick by Biden following the debate, Karl reports, writing: “Calls to lawmakers, Harris believed, could be misinterpreted as the early stages of an effort to secure the nomination for herself. If she called Democratic members, those members could later disclose that they had spoken to her and misrepresent the purpose of the call.”

Biden went on to endorse Harris just 27 minutes after ending his own campaign — after the vice president warned that waiting longer, as the president’s advisers initially planned, could trigger competition for the party nomination.

“It needed to come immediately,” Karl writes of the then-veep’s insistence. “Otherwise, she argued, Biden would be opening the door to an ugly fight for the nomination.”

Harris went on to lose to Trump in an Electoral College landslide, becoming the first Democratic presidential candidate in 20 years to lose the popular vote.

“Retribution” hits bookstores Oct. 28.