“Biden’s temper, and his willingness to unleash it in small group settings, was one reason the people closest to him often avoided pushing him too hard to change his ways or take a particular course of action,” write journalists Jonathan Allen and Amie Parnes in Lucky: How Joe Biden Barely Won the Presidency.

Biden’s so-called Irish temper, a term the president himself often uses despite its racially charged nature, tended to erupt at younger aides. Greg Schultz and Kate Bedingfield, both in their thirties, were “most likely to get their ears boxed for pushing back on Biden’s ideas,” the authors write. When he wasn’t screaming at them, Biden “had a tendency to talk down” to the “delicate” youngsters.

The authors recount a meeting in early 2019 when a “visibly irritated” Biden “hollered at” and “unloaded on Schultz,” who had (rather ironically) advised the candidate to “adjust his tone with younger voters.” These new details about Biden’s inability to take constructive criticism without lashing out raise serious questions about his fitness to serve as commander in chief and could prompt a discussion about invoking the 25th Amendment.

“Ultimately, Biden made his own decisions, and got cranky when they were made for him,” the authors write. “Nobody wants to suffer one of his epic tongue-lashings.” The candidate “didn’t like to be questioned,” which meant that even his most senior aides “conspicuously avoided confrontation” because no one wanted to be on the receiving end of Biden’s rage.

Biden’s volatile temper almost got the best of him, the authors report, during a July 2019 primary debate, when his future running mate, Kamala Harris, attacked him for befriending racist senators and promoting racist legislation. Biden was “pissed” and “steaming inside” following Harris’s broadside, which would prove to be the high-water mark of her presidential campaign. During a commercial break, a seething Biden turned to his podium neighbor Pete Buttigieg and stammered, “This is just a bunch of bullshit!”

“Obama’s fears about Biden and his team ran deep—deeper than defeat,” journalists Jonathan Allen and Amie Parnes write in Lucky: How Joe Biden Barely Won the Presidency. “Obama worried that his former vice president would embarrass himself on the campaign trail and that the people around him would not be able to prevent a belly-flop.”

Obama, who had vowed to remain neutral during the Democratic primary in 2020, had repeatedly urged Biden not to run for president. “It had stung Biden badly in 2015 when Obama made clear his preference for Hillary Clinton,” the authors write. “Adding insult to injury, Obama’s advisers told Biden aides back then that they didn’t think he could beat Clinton. They pressured him to get out of the way.”

Obama’s lack of support in 2016 was especially insulting to Biden because the former VP thought Hillary was a “terrible candidate” who would be easy to beat.

In 2019, Obama tried once again to talk Biden out of running. “You don’t have to do this, Joe, you really don’t,” the former president told Biden, according to the New York Times. Allen and Parnes explain that Obama’s “reluctance to bless Biden’s candidacy” was born out of a “fear that Biden would dishonor himself with a bad campaign.”

The new revelations about Obama’s views on Biden are supported by previous reporting. Biden has said the former president “was not encouraging” heading into the Democratic primary in 2020. During the campaign, Obama reportedly assessed that Biden “really doesn’t have it” and warned Democrats not to “underestimate Joe’s ability to fuck things up.”

Even after Biden won the Democratic nomination, Obama declined to donate any money to his general election campaign, despite being a multimillionaire. Just days after Biden’s victory in November, the former president stole the spotlight by launching a book tour.