The criticism from ex-Obama staffers aimed at President Biden, including calls for him to exit the 2024 presidential race, serve as a stark reminder of the well-known tensions between the former White House duo that go back nearly two decades.

The often testy relationship between Biden and Obama reportedly began shortly after the latter's election to the Senate in 2004, when both men served on the Senate Foreign Relations Committee. Obama, according to The New York Times, wasn't fond of Biden's often-long-winded speeches to the point where, on one occasion, he passed a note to a colleague reading, "Shoot. Me. Now."

The two eventually found themselves facing off for the 2008 Democratic presidential nomination, where Biden, while announcing his campaign, controversially referred to Obama as "the first mainstream African-American who is articulate and bright and clean and a nice-looking guy."

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Former President Obama and President Biden. (Getty Images)

The intense blowback from the comment led to an apology from Biden, and Obama telling reporters, "I have no problem with Joe Biden." 

Biden eventually dropped out of the race after a dismal showing in the Iowa caucuses, but was subsequently picked by Obama to be his running mate. The two ultimately defeated Republican nominees John McCain and Sarah Palin.

The first few months of their administration reportedly saw frequent disagreements between the two, including a clash over Obama publicly diminishing Biden while speaking to reporters — which he later agreed with an upset Biden to avoid doing — and eye rolls from the former while the latter spoke during meetings.

Biden was reportedly frustrated with Obama's cautious decision-making process, and disagreed with him on a number of issues, including sending more troops to Afghanistan at the request of military leadership.

Despite the disagreements, the two eventually developed a close partnership, and even friendship, before Obama reportedly dismissed a suggestion by close advisers to replace Biden in the 2012 re-election campaign with then-Secretary of State Hillary Clinton.

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President Obama smiles alongside Vice President Biden before signing healthcare insurance reform legislation during a ceremony in the East Room of the White House in Washington, D.C., on March 23, 2010. (Saul Loeb/AFP via Getty Images)

Obama was close to Biden and provided strength and support for his family in the lead up to, and following, the death of his son, Beau Biden, from a form of brain cancer, but later worked to convince his vice president not to seek the 2016 Democratic nomination in favor of Clinton.

"The president was not encouraging," Biden later acknowledged, according to The New York Times. He never publicly expressed disappointment in Obama favoring Clinton, but did reportedly feel he would have been a stronger opponent to then-Republican nominee Donald Trump.

When Biden did eventually launch another presidential campaign in 2019, Obama decided not to endorse him, and instead opted to let the primary process play out. He did eventually offer his endorsement in August 2020 after Biden had secured the nomination.

The tension between the two, despite being friends, appeared to have gone nowhere throughout the campaign when Obama reportedly expressed doubts about Biden's fitness for office.

"Don’t underestimate Joe’s ability to f--- things up," a Democratic source recalled Obama saying on one occasion, according to Politico.

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This White House handout photo shows President Obama and Vice President Biden in the Oval Office of the White House during the President's Daily Economic Briefing on July 30, 2009. (Pete Souza/AFP via Getty Images)

Biden has often compared himself to Obama throughout his presidency, even to the point of frequently using the phrase, "Obama would be jealous," when talking about an accomplishment, according to a report from Axios earlier this year.

Biden's disappointing showing in the first presidential debate last month drove many former Obama advisers and allies to call for his exit from the race, despite the former president initially defending him. Those calls included former adviser Jon Favreau, widely known as one of the "Obama bros" during his time at the White House.

Favreau, who attended the same Los Angeles fundraiser that actor George Clooney referenced in his damaging New York Times guest essay calling on Biden to drop out of the presidential race, said during an appearance on CNN earlier this week that "Clooney was exactly right."

Clooney wrote in his guest essay that the Biden who showed up at the fundraiser was "not the Joe ‘big F-ing deal’ Biden of 2010. He wasn’t even the Joe Biden of 2020. He was the same man we all witnessed at the debate."

Ex-Obama adviser David Axelrod has also repeatedly criticized Biden, saying Friday while appearing on CNN that Biden "really needs a royal flush to win this race" against former President Trump.

"There are certain immutable facts of life," Axelrod said in a separate CNN interview while discussing Biden's age and leadership. "Those were painfully obvious on that debate stage. The president just … hasn't come to grips with it. He’s not winning this race."

Ex-Obama adviser David Axelrod, right, criticized President Biden's debate performance and ABC News interview. (AP Photo / Getty Images)

From left: former Obama adviser Jon Favreau, President Biden and actor George Clooney. (Getty Images)

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Reports have also surfaced that Obama has been working "behind the scenes" to force Biden out of the race. Multiple media outlets reported Thursday morning on Obama's alleged efforts, including Politico, which stated that the former president had been given a "heads-up" by Clooney about his guest essay.

A source close to Obama declined to comment on the reports but pointed Fox News Digital to the former president's statements in support of Biden, both at the Los Angeles fundraiser that became the subject of Clooney's op-ed and following the debate.

White House press secretary Karine Jean-Pierre on Friday responded to a recent claim by Trump that Obama "never respected" Biden throughout their time in office. She said Biden and Obama have "a close relationship," but couldn't speak to the details of any recent call or conversation between the two.

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