President Joe Biden celebrates his 80th birthday with brunch hosted by First Lady Jill Biden

WASHINGTON -- President Joe Biden turns 80 years old on Sunday, becoming the first octogenarian to ever serve in the highest office of the United States.

The unique milestone of Biden's birthday comes as the president faces speculation about whether he will mount a reelection run and dredges up questions about whether he's too old to serve another term.

The president is celebrating his birthday in Washington with a brunch hosted by first lady Jill Biden, according to White House press secretary Karine Jean-Pierre. Members of Biden's family already in town celebrating his granddaughter's wedding at the White House on Saturday are expected to be in attendance.

The wedding's timing, two people familiar with the planning had told CNN, was not a coincidence -- noting the "age issue" is never something Biden wants to highlight. Jill Biden on Sunday tweeted two photos of her dancing with her husband at the Saturday night reception, saying, "There's no one else I'd rather dance with than you. Happy Birthday, Joe! I love you."

The president has political momentum on his side ahead of a potential reelection bid -- having been able to maintain a Democratic majority in the Senate and thwart the historical political tides of a resounding Republican wave in Congress. There was also the lukewarm political support his slightly younger predecessor, Donald Trump, received when he announced his recent decision to run for president in 2024.

But Biden has not been able to shake voters' apprehensions about his age, with rhetorical gaffes and literal stumbles at times reinforcing concerns about his health and mental acuity.

Biden would be an unprecedented 86 years old by the end of his second term if he were to run and win his reelection. By comparison, some of the oldest past living presidents still had years on Biden -- Trump left office at the age of 74 and Ronald Reagan left office after his two terms at 77 years old.

The president, for his part, maintains that voters concerned about his age should see his record of accomplishments since taking office.

"Well, they're concerned about whether or not I can get anything done. Look what I've gotten done," Biden told CNN's Jake Tapper in October. "Name me a president in recent history that's gotten done as much as I have in their first two years."

Biden said last month that while he has not made a formal decision about running for reelection in 2024, it is his "intention" to do so. But he's long said it's a decision both he and his family will decide on together. And Saturday's wedding marks a kickoff of sorts for the tight-knit Bidens to begin earnest discussions over whether their patriarch should seek a second term.

And the president isn't the only Washington power reckoning with pressures to bow out. On the other end of Pennsylvania Avenue, Nancy Pelosi, 82, recently announced plans to step down as House speaker, celebrating Democrats ushering in a new generation of leadership. And Senate Minority Leader Mitch McConnell, 80, faced his first challenger to lead the Republican conference in 15 years -- though that challenge was unsuccessful.

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