After almost a month of high-pressure calls for him to make way for a younger alternative, following his disastrous presidential debate performance, President Joe Biden says he will end his bid for a second term.

Biden’s announcement effectively upends U.S. presidential politics with just four months to go before the general election, and it comes just weeks before Democratic National Convention starts on August 19, leaving his party very little time to anoint a successor and re-engage their efforts against a comparatively unified Republican Party and the campaign of former President Donald Trump.

The 81-year-old 46th President said that he’s proud of his record, but that it has become apparent it’s time to pass the torch.

“I believe it is in the best interest of my party and the country for me to stand down and to focus solely on fulfilling my duties as president for the remainder of my term,” Biden said in a statement shared to his social media accounts.

In making his announcement, Biden thanked Vice President Kamala Harris for her service and later endorsed her candidacy to replace him at the top of the party ticket.

“My very first decision as the party nominee in 2020 was to pick Kamala Harris as my Vice President. And it’s been the best decision I’ve made. Today I want to offer my full support and endorsement for Kamala to be the nominee of our party this year. Democrats — it’s time to come together and beat Trump. Let’s do this,” he wrote.

Harris said that Biden’s decision to step aside is a “selfless and patriotic act.”

“President Biden is doing what he has done throughout his life of service: putting the American people and our country above everything else. I am honored to have the President’s endorsement and my intention is to earn and win this nomination,” she said in a statement shared by their mutual campaign.

Trump was quick to respond to the news, saying that Biden was never fit to hold the Oval Office in the first place.

“He only attained the position of President by lies, Fake News, and not leaving his Basement. All those around him, including his Doctor and the Media, knew that he wasn’t capable of being President, and he wasn’t – And now, look what he’s done to our Country, with millions of people coming across our Border, totally unchecked and unvetted, many from prisons, mental institutions, and record numbers of terrorists. We will suffer greatly because of his presidency, but we will remedy the damage he has done very quickly,” he wrote on his Truth Social media platform, capitalization his.

“Crooked Joe just got knocked out, so now I’ll have to do it a FOURTH TIME!!!” he added later.

Former President Bill Clinton and former Secretary of State Hillary Clinton, who narrowly lost to Trump in 2016, said they are “honored to join the President in endorsing Vice President Harris and will do whatever we can to support her.”

Biden’s decision to step down follows weeks of one liberal lawmaker after another coming out against his continued participation in the race. His debate performance was the start of the avalanche of calls for him to step aside, but the problem compounded following other public performances where the president did not appear as well equipped as he did even just four years ago.

What precisely happens next in Democratic politics is anyone’s guess.

DNC rules don’t allow Biden to just award delegates pledged to him to another candidate, not even the one sharing the ticket with him. That means Democrats will head into an open convention next month, with more than 4,000 delegates up for grabs for anyone opportunistic enough to seek them.

DNC Chairman Jaime Harrison acknowledged the party now has unprecedented work to do and very little time to do it.

“This process will be governed by established rules and procedures of the Party. Our delegates are prepared to take seriously their responsibility in swiftly delivering a candidate to the American people,” he wrote.

Former President Barack Obama said in a statement that the party “will be navigating uncharted waters in the days ahead.

“But I have extraordinary confidence that the leaders of our party will be able to create a process from which an outstanding nominee emerges,” he said.

According to Trump’s campaign managers Susie Wiles and Chris LaCivita, Biden’s announcement he can’t run is the same as an admission he can’t continue holding office through January of 2025.

“The question then to Kamala Harris is simple: knowing that Joe Biden withdrew from the campaign because of his rapidly deteriorating condition, does Harris believe the people of America are safe and secure with Joe Biden in the White House for six more months,” they said in a statement.

One thing is for certain, according to Casey Burgat, the director of the Legislative Affairs program at the Graduate School of Political Management at George Washington University: the Democrats have just opened themselves up to a whole host of new problems.

“Biden’s dropping out does raise interesting questions about whether or not the voters’ will was reflected or if party leaders and donors were the one calling the shots. Both are true, but Republicans are sure to hammer the point that the liberal elites ignored everyday voters in an attempt to change the rules of the game once it became clear they couldn’t win fairly,” he said.

Republican House Speaker Mike Johnson echoed the call for Biden to resign if he is not fit enough to run for office. In a statement, Johnson said, “November 5 cannot arrive soon enough.”

Johnson also on Sunday predicted that Republicans would challenge whether Democrats can legally replace Biden as the nominee after he won a run of primaries across the country.

“I think they have got legal hurdles in some of these states, and it’ll be litigated, I would expect, on the ground there and they will have to sort through that. They have got a real problem,” Johnson said on CNN’s ”State of the Union.”

Herald wire services contributed.

Vice President Kamala Harris was endorsed by President Joe Biden on Sunday after he stepped aside amid widespread concerns about the viability of his candidacy. (Photo by Chris duMond/Getty Images)