President Joe Biden celebrated his 81st birthday on November 20, 2023 in a low-key family celebration, as his age and concerns about his fitness for office continue to be a topic of debate as he prepares for a reelection campaign. Recent polls show a majority of voters think Biden lacks the stamina and sharpness for the presidency. Younger voters in particular raise Biden's age as a concern. Biden, already the oldest U.S. president, would be 86 at the end of his second term if reelected in 2024, surpassing Ronald Reagan who was 77 at the end of his tenure. Biden's reelection may hinge on whether voters see his decades of experience as more valuable than concerns about his advanced age.