By Tom Gantert and Dan McCaleb | The Center Square

President Joe Biden ended his bid for reelection Sunday with a written announcement on social media sites, opening the door for Vice President Kamala Harris or another top Democrat to replace him atop the ticket.

In a statement posted to X, Biden said he is stepping aside “in the “best interest of my party and the country.”

“It has been the greatest honor of my life to serve as your President,” Biden said. “And while it has been my intention to seek reelection, 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 held no news conferences, made no public appearances, and answered no questions about his decision Sunday, despite weeks of insisting he was remaining in the race after more and more Democrats insisted he exit due to declining cognitive abilities.

Biden also endorsed Harris to succeed him.

“My very first decision as the party nominee in 2020 was to pick Kamala Harris as my Vice President,” he said in a second statement. “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.”

The Clintons, former President Bill and Democratic presidential candidate Hillary, also endorsed Harris. As of Sunday night, prominent Democrats former President Barack Obama, former Speaker of the House Nancy Pelosi, Senate Majority Leader Chuck Schumer and U.S. House Minority Leader Hakeem Jeffries had yet to endorse Harris or any other potential candidate.

Responding to the withdrawal news, GOP nominee and former President Donald Trump said Biden wasn’t fit to run for president to begin with.

“Crooked Joe Biden was not fit to run for President, and is certainly not fit to serve – And never was!” the 45th president wrote on Truth Social. “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.”

Many Republicans called for Biden to resign the presidency immediately, arguing that he if’s not fit to run for office, then he’s not fit to serve.

The historic withdrawal comes just weeks before the Democratic National Convention is set to take place Aug. 19 in Chicago, where Biden’s pledged delegates will face tough decisions on who to replace him with, regardless of Biden’s endorsement.

Concerns over Biden’s age, declining cognitive abilities and physical health led more and more elected Democrats in Congress to call for his exit, seemingly on a daily basis. Earlier Sunday, U.S. Sen. Joe Manchin, I-West Virginia, joined the calls for the president to exit the race.

Biden’s support among Democrats began to freefall after his performance in the June 27 debate with Trump, when Biden stumbled over his own words and often lost his train of thought.

At a NATO news conference a couple of weeks later, Biden referred to Kamala Harris as “Vice President Trump” when asked if he thought Harris was ready to be president if he were to step aside, one of many gaffes during the summit.

During the Republican National Convention in Milwaukee last week, where Trump officially accepted the GOP nomination for president just days after a failed assassination attempt on his life at a campaign rally in Pennsylvania, Biden was hunkered down at his Delaware home, recovering from his third bout with COVID-19.

Biden has not fared well in 12 major polls tracking the 2024 general election in recent weeks, leading down-ballot Democratic candidates for Congress to raise concerns that his declining support could help Republicans to retake the White House and the U.S. Senate and solidify their majority in the U.S. House.

Trump led by an overall average of 3 points in the 12 polls. Biden only led in one poll, where he had a 2-point edge in the NPR/PBS/Marist poll. Trump and Biden were tied in the ABC News/Washington Post poll. Trump led in the 10 other polls as of Thursday.

In The Center Square Voters’ Voice Poll of nearly 2,300 likely voters, conducted after the June 27 debate but before the attempted assassination on Trump, Biden’s deficit grew to three full percentage points nationally. The poll has a margin of error of 2.1%.

Until Sunday, Biden defiantly opposed calls to step aside.

While his June debate performance seemed to seal Biden’s fate, his deteriorating cognitive abilities made news months earlier.