Questions swirl now, in his own party as well as broadly in the country, about whether he’s got what it takes to go for the summit again.

The oldest president in U.S. history, Biden hits his milestone birthday at a personal crossroads as he and his family face a decision in the coming months on whether he should announce for reelection. He’d be 86 at the end of a potential second term.

Biden aides and allies all say he intends to run — and his team has begun quiet preparations for a campaign — but it has often been the president himself who has sounded the most equivocal. “My intention is that I run again,” he said at a news conference this month. ”But I’m a great respecter of fate.”

“We’re going to have discussions about it,” he said. Aides expect those conversations to pick up in earnest over Thanksgiving and Christmas, with a decision not until well after New Year’s.

Biden planned to celebrate his birthday at a family brunch in the White House on Sunday.

To observe Biden at work is to see a leader tap a storehouse of knowledge built up over a half century in public office as he draws on deep personal relationships at home and abroad, his mastery of policy and his familiarity with how Washington works or doesn’t. In short, the wisdom of the aged.

“There is something to be said for experience,” said Dartmouth College historian Matt Delmont as he noted the dozens of global leaders in their 80s.

But to observe Biden is also to see him walk now often with a halting gait, in contrast to his trotting on stage on election night 2020.

It is to see him take a pass on a formal dinner with other world leaders without a real explanation, as happened on his trip abroad this past week, when he twice spoke of visiting Colombia when he meant Cambodia. Some supporters wince when he speaks, hoping he gets through his remarks OK.

House Speaker Nancy Pelosi’s decision, at age 82, to pull back from leadership and let a new generation rise may spill over into Biden’s thinking and that of his party as Democrats weigh whether they want to go with a proven winner or turn to the energy of youth.

Among the questions Pelosi’s move raises, said Kathleen Hall Jamieson, an authority on political communications at the University of Pennsylvania: “Even if one is highly competent and successful, is there a point at which one should step aside to give others the opportunity to lead just as others stepped aside to make it possible for you to do so?

“Pelosi’s decision makes such questions more salient in the context of Biden’s 2020 statement that he was the bridge to a new generation of leaders.”

Some allies see Biden’s blunders as an increasing vulnerability in the eyes of voters as he’s grown older.

In an AP survey of the electorate this month, fully 58% of voters said he does not have the mental capability to serve effectively as president. That was a grim picture of his standing now, not just looking ahead to another potential term. Only 34% said he’s a strong leader.