Joe Biden's time in public office is now behind him, but his age and mental acuity have become a litmus test for the next leaders in his party.
A new book that alleges White House aides covered up Biden's physical and mental decline has put the questions about Biden's health back in the spotlight, months after former Vice President Kamala Harris lost to President Donald Trump. Several potential Democratic contenders for the 2028 nomination in recent days have been asked whether they believe Biden was declining in office or whether he should have sought reelection before a disastrous debate performance led to his withdrawal.
Many Democrats would prefer to focus on Trump's second term. Trump has done his best to prevent that - mentioning Biden's name an average of six times per day during his first 100 days in office, according to an NBC News analysis - and Republicans have followed his lead, betting that voters frustrated by Trump's policy moves will still prefer him over memories of an unpopular presidency.
In the race for Virginia governor, one of this year's highest-profile contests, Republican Winsome Earle-Sears is running a pair of television ads tying Democrat Abigail Spanberger to Biden, with images of the two hugging and the former president calling her a friend.
"The stench of Joe Biden still lingers on the Democratic Party," Democratic strategist Sawyer Hackett said. "We have to do the hard work of fixing that, and I think that includes telling the truth, frankly, about when we were wrong."