WASHINGTON (CNN) — US President Joe Biden celebrates his 81st birthday this Monday with a discreet family celebration.

But while the first family kept the celebrations quiet and inconspicuous, the moment highlighted their biggest liability in the campaign: their advanced age and, with it, their diminished physical and mental abilities among voters.

This Monday morning, Biden confused pop stars Britney Spears and Taylor Swift as he presided over the annual Thanksgiving turkey pardon.

Being the national Thanksgiving turkey, he said, is “a lot harder than getting tickets to the Revival tour or Britney’s tour; it’s a little hot in Brazil right now,” appearing to confuse Spears with Swift, who is on tour in South America.

He also delivered several jokes about his age.

“I want you to know that turning 60 is hard, hard,” the turkey apologetic told the audience with a laugh. While commemorating the event’s 76th anniversary, he joked that the first edition was “not there”.

White House and Biden campaign officials privately acknowledge that age is a vulnerability and are working to eliminate potential gaffes and energize the program. After Biden’s annual physical, this year he was prescribed custom orthotics to help his feet determine It enjoys a “hard walk”. In recent months, Biden began using small, narrow stairs to board and disembark more frequently while flying on Air Force One.

Biden has also made an effort to invite reporters on his vacation bike rides in Delaware, occasionally stopping to put on his helmet and answer questions. (The president is an avid Peloton user in the White House.)

However, age liability is becoming evident almost daily. A series of recent surveys, including one New CNN poll, indicate that this is a chronic problem among voters. Critics raise it every chance they get.

On Saturday, former President Donald Trump, the front-runner for the GOP nomination, called Biden a “stupid person” who “can’t get out of this situation. Whatever he takes it will wear off,” prompting applause from the crowd. In Fort Dodge, Iowa, on Sunday, Florida Gov. Ron DeSantis, 45, commented that “fatherhood has not been defeated,” and noted the age of both Biden and Trump, 77. An interview with CNN’s Jake Tapper.

Biden is already the oldest president in history, surpassing Ronald Reagan at 77 at the end of his second term. If elected in 2024, Biden would be 86 at the end of his second term. Meanwhile, Trump, who is approaching 83, would become the oldest president in history if elected.

Biden’s advisers argue that there is a double standard — and complain that the media focuses more on Biden’s age than Trump’s. Still, they insist that voters are focused on other things and that age will not be a deciding factor come November.

“I don’t think the campaign should focus on anything other than the winning record,” said Rep. Robert Garcia, Democrat of California, a member of the Biden campaign’s national advisory board. “Everything else about other people’s biographies or their birthdays doesn’t matter. People want to know what they have done and what they are going to do.

On Monday, Biden’s birthday milestone will pass without much fanfare. Its date includes the tradition of giving thanks before the annual turkey pardon. He is expected to receive briefings from his national security advisers on global crises.

The campaign is not ignoring Biden’s birthday, aides told CNN. A Democratic National Committee official told CNN that the plan is to mark the occasion with a social media post every year since 2011, except for the three years he’s been a candidate or potential nominee.

The Democratic Congressional Campaign Committee is also urging supporters to sign a virtual birthday card for the president.

Biden and Trump are trying to refine the age issue

The former president, who has been an outspoken critic of Biden on nearly everything, showed unusual restraint when directly attacking the president’s age.

It’s an important issue for both of them, and Trump seems aware of the dangers of distinguishing himself with Biden because of their exact age difference of three years and five months. In a recent interview, Trump avoided directly attacking Biden’s age.

“He’s not too old, he’s incompetent,” Trump told Megyn Kelly in an interview on her Sirius XM show last month.

“Age is interesting because some people are very intelligent and others lose it, but it’s lost in their 40s and 50s,” he continued. “But no, he’s not too old. “He’s too incompetent.”

In turn, the Biden campaign has begun to show that it is not afraid to attack there either.

“Is Donald Trump OK?” An official Biden campaign account said A publication earlier this month on social media platform X. It featured a composite video of Trump’s gaffes, including confusing the city he was from, calling former President Barack Obama his “main political opponent” and mixing up Hungarian Prime Minister Viktor Orbán’s country of origin.

For his part, Biden sometimes laughs at his age.

“I’m not like that, but I’m 180. “I’ve been here a long time,” he joked to donors at a recent fundraiser.

But most of all, he and other officers draw on their age as a source of wisdom and experience.

“I have more experience than any president in American history,” he said at another fundraiser. “One of the things that comes with age is confidence and wisdom.”

John Kirby, strategic communications coordinator for the National Security Council, suggested that Biden’s experience, particularly in the foreign policy arena, has been positive.

“I’ve never seen a more turbulent world, and at a time like this, when things are as turbulent, uncertain, and sometimes, terrifying, as they are now, you need someone who has seen the world.” Who understands the history behind the place,” Kirby told CNN.

Biden “brings a steady hand, wisdom and experience to the leadership of foreign policy,” Kirby said. “It’s irreplaceable.”

White House advisers point to the president’s ability to undertake arduous trips and high-stakes meetings with world leaders as evidence of his resilience. He often wears out his colleagues, they say.

Kirby pointed to instances where Biden pressured colleagues to add events or commitments to busy schedules. He added a call with the Emir of Qatar on Friday morning ahead of APEC summit meetings in California. He also added an impromptu briefing to reporters on Air Force One after a grueling trip to Tel Aviv, Israel, last month.

Surveys and “father time” issues

Polls show the question lingers. A AP-NORC survey In August, 77% of respondents agreed with the statement that Biden is too old to effectively serve another four years as president, while 51% of respondents said the same for Trump.

A CNN National Poll Conducted by SSRS earlier this month, only 25% of registered voters say Biden has the stamina and intelligence to serve as president effectively, while 53% trust Trump.

In the most recent CNN poll conducted by the University of New Hampshire, 56% of Democratic voters in the Granite State cited the president’s age when asked to name Biden as a candidate.

When New Hampshire adults were surveyed on a very broad list of the candidates’ personal traits, Trump did worse than Biden on each of them (temperament, honesty and integrity, policy positions, decision-making ability), except for physical and mental health.

A majority of voters (58%) gave a poor rating of Biden’s physical and mental health, while 53% gave Trump poor marks. Still, those numbers reflect clear voter concerns on the issue for both candidates.

Of course, it’s possible that Biden will face a different opponent in the general election. Former South Carolina Gov. Nikki Haley, who is second in the New Hampshire GOP primary poll, has proposed “mandatory mental capacity testing for politicians over 75.”

The view of the younger generation

The president’s age is often one of the first topics to come up in conversations with young voters, often the subject of questions about whether he’s fit for the job.

“I don’t want to say that his age is a deterrent to young voters,” said Kerry Singleton, a senior at Morehouse College in Atlanta.

Rachel Carroll, who graduated last year from Clark Atlanta University, said she believes Biden belongs to another era, where he doesn’t understand the progressive views of many Democratic voters.

“No offense, but yeah, he’s a little old for me,” Carroll said, adding that Trump should be the same age as Americans. “We live in completely different times because they don’t understand what we’re going through now.”

Nabila Islam Parks, the youngest woman elected to the Georgia state Senate last fall, said she doesn’t think age is the main concern about Biden. He said questions about his government’s handling of the Middle East and its worldview were more pressing.

“As long as we think he reflects our values,” he said, “age shouldn’t be an issue.”

Progressive groups seeking to mobilize young voters said they don’t believe Biden’s age will ultimately be a significant factor in swinging young voters to him in the polls.

“It’s very low on the list of things we think about and things that actually affect our lives,” said Jake Lobel. Care.”

CNN’s Jeff Zeleny, Camila DeChalus, Kristen Holmes and Arlette Saenz contributed to this report.