Just months after party leadership shielded President Biden from any kind of significant primary challenge, Democrats are suddenly turning on their presumptive nominee and seeking to swap him out mere weeks before his nomination for re-election becomes official.

Biden’s devastating debate performance last week triggered a seismic shift in the party’s public outlook regarding the president’s ability to run for a second term. Many who had previously professed nothing but loyalty to the 46th president are now calling for him to step aside and allow Vice President Kamala Harris or another promising Democrat to take his place.

But the president doesn't appear ready to exit, saying at a Wisconsin rally on Friday, "I am running and going to win again."

The contentiousness could have been avoided, however, if party leadership had allowed a vigorous challenge to Biden's candidacy and chose not to upend primary precedent to favor the incumbent. 

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President Biden

President Biden speaks during a campaign event at the Martin Luther King Recreation Center in Philadelphia April 18, 2024. (Hannah Beier/Bloomberg via Getty Images)

The Democratic Rules and Bylaws Committee voted earlier this year to adopt Biden's own proposal to have South Carolina, a strong state that helped catapult Biden toward the nomination in 2020, vote first on the Democrats' nominating calendar in 2024. Under his proposal, New Hampshire and Nevada, where he was weaker in 2020, would hold primaries a few days later. 

New Hampshire rejected the new rules in the 2024 primary, and Biden’s name did not appear on the primary ballot. But he still won by a wide margin due to voters who wrote in his name. 

Biden also delayed committing to a debate with his presumptive rival for the presidency for months. Biden said it "depends" on the former president’s "behavior" whether he agreed to a debate when asked by reporters in March about a faceoff with Trump.

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President Joe Biden

President Biden at the White House Dec. 13, 2023, in Washington, D.C. (Chip Somodevilla/Getty Images)

After Super Tuesday, Trump invited Biden to debate "anytime, anywhere, anyplace." But the Biden campaign dismissed those calls as Trump being "thirsty for attention." 

"I know Donald Trump's thirsty for attention and struggling to expand his appeal beyond the MAGA base, and that's a conversation we'll have at the appropriate time in this cycle," a Biden campaign spokesperson said at the time.

Although Biden’s disastrous debate performance last week set off alarm bells about the president’s cognitive decline, concerns about the president’s mental fitness lingered long before the debate. 

"The administration was above conspiratorial chitchat that entertained seriously scenarios in which the president was suffering from a shocking decline most Americans were not seeing," Olivia Nuzzi wrote in a recent New York Magazine story. 

"If the president was being portrayed that way, it was by his political enemies on the right, who promoted through what the press office termed ‘cheap fakes’ a caricature of an addled creature unfit to serve. They would not dignify those people, or people doing the bidding of those people, with a response."

Now, just 45 days away from the Democratic National Convention, Biden’s campaign is scrambling to help his supporters maintain their confidence in the president and dispel calls for him to step aside, even as key fundraisers have halted campaign donations.

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Biden at the White house

President Biden walks on the South Lawn of the White House after arriving aboard Marine One in Washington, D.C., Sept. 4, 2023. (Michael Reynolds/EPA/Bloomberg via Getty Images)

Democratic Massachusetts Gov. Maura Healey publicly urged President Biden to "listen to the American people" and consider whether he is the best person for the party to put forward as it again tries to defeat Trump in November.

"President Biden saved our democracy in 2020 and has done an outstanding job over the last four years," Healey said in a statement distributed by her political committee Friday. "I am deeply grateful for his leadership. And I know he agrees this is the most important election of our lifetimes.

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"Over the coming days, I urge him to listen to the American people and carefully evaluate whether he remains our best hope to defeat Donald Trump. Whatever President Biden decides, I am committed to doing everything in my power to defeat Donald Trump."

At an Independence Day event Thursday, Biden seemed defiant, telling a crowd at the White House he's "not going anywhere."