President Biden knew something wasn't going well as soon as he walked off the stage in Atlanta on Thursday night. After the first few minutes of his raspy, rambling and at times incoherent speech, he turned to his wife, Jill Biden.
It may have been the lowest point of Biden's long political career, but what happened next in his final presidential election was always going to depend on her: his wife of 47 years, who came into his life decades ago and, while reluctant to enter politics, was fully embracing his dreams and his belief that he would one day reach the White House.
Now her 81-year-old husband was watching her as she finished a harrowing 90-minute performance on stage.
The first lady's message to him was clear: They've lost before, but she was committed, and he, they were going to keep campaigning. She just thought it was a bad night, according to people close to her. And bad nights end.
“The bond between them cannot be explained simply by the fact that they were in the trenches together,” said Elizabeth Alexander, a spokeswoman for the first lady, who has accompanied Biden since his days as a senator.
So Dr. Biden spent the 24 hours after the debate expressing confidence and poise as she effusively praised her husband, testing her decades of experience as a political wife. But like the president, she is an intuitive political messenger who can sense the mood of a crowd. She knows that along with cheering supporters, there will suddenly be many who will accuse her of letting the old man put his tired foot forward.
If Biden seriously considers dropping out of the race and replacing him with a younger candidate, the first lady would be the most important person, other than the president himself, in making that decision.
“Jill is the final and most important voice. She knows Biden well, she loves him dearly and she knows everything about him. Most of the big decisions are ultimately made by Valerie and Jill,” said John Morgan, one of Biden's top donors, referring to the president's sister who has run nearly all of Biden's campaigns.
In fact, as major Democratic donors communicated by text, phone or in person on Friday, one of the most direct questions they asked one another was whether anyone knew how to meet or speak with the first lady.
After nearly half a century in politics, the Bidens see themselves as guys in the long game, and now neither wants the story of the president’s long political career marked by tragedy, resilience and insatiable ambition to end on a stage in Atlanta, across from the podium of former President Donald J. Trump, whom they both detest.
“He wants to win, and she wants to win for him and for the country,” Alexander said. “She's his biggest supporter and defender because she believes in him, and she's worried about the future of the country if the outcome is the other way around.”
Speaking before supporters on Friday, the first lady supported a point made by Democratic leaders, including Vice President Kamala Harris, that Biden's lackluster performance does not invalidate years of legislative success.
“As Joe said today, he's not young,” Dr. Biden told a group of donors gathered in Manhattan on Friday afternoon, his third stop since leaving Atlanta. “After the debate last night, he said, 'Jill, I don't know what happened. I didn't feel very good.' And I said, 'Look, Joe, I'm not going to define four years of your presidency in 90 minutes.'”
Dr. Biden understood that debate night was a major misstep. The president should have entered the debate room and addressed concerns about his age. But after six days of preparation and mock debates at Camp David, he took the stage with nothing to show for it except a raspy voice. (The White House announced that the president had a cold.)
She had heard Trump mock Biden. “I have no idea what the hell he said at the end of that sentence,” Trump said after Biden got an answer wrong on immigration. “I don't think he knows what he said, either.”
She sat in the front row of the courtroom to listen as the former president attacked Biden's son, Hunter Biden, whom she raised as a child and attended his recent trial on firearms charges, and listened as the world was told the worst moments of his addiction.
And she watched as Trump continued to speak angrily, while her husband's eyes were wide and his mouth was agape, angrily taking in what was happening but barely able to fight back.
Dr. Biden then held hands with the president as he stalked down the stairs. The moment quickly went viral: At a campaign viewing party the Bidens attended immediately after the debate, she praised her husband's performance. But other critics saw her as virtually patting him on the head for simply making it through the debate.
“You answered all the questions and knew all the facts,” she said. “So what did Trump do?”
“That's a lie!” the crowd shouted.
The first lady, who had avoided any major controversy for the past three and a half years, was suddenly under fire from people who believed she was trying to cover up his declining performance.
“What Jill Biden and the Biden campaign did tonight to Joe Biden – bringing him onstage and challenging him to an unarmed battle of wits – is, simply put, elder abuse,” Rep. Harriet M. Hageman, a Republican from Wyoming, said in a social media post.
The Drudge Report, a prominent conservative website whose writer Matt Drudge has expressed displeasure with Trump, published an unflattering photo of the Bidens on Friday with the headline “Ruthless Jill Clings to Power.”
The first lady and her advisers have noticed similar allegations appearing on conservative websites before and have been leaking into the mainstream. Mr. Alexander said Mr. Biden sees his “vague” role as “an act of service, not some fictitious power grab invented in the dark corners of the internet.”
She added that the first lady sometimes felt shackled by the demands of a role filled with expectations and hidden dangers.
“We need support, but not so much that our motives become questionable,” Alexander said, placing much of the blame on the internet, bots and right-wing organizations fueling “conspiracy theories of all kinds.”
Advisers to the president and first lady have downplayed the idea that she has the power to unilaterally halt the president's reelection campaign and pave the way for another candidate four months before the election. They acknowledge her unique influence and power in Mr. Biden's life but say he controls his own campaign.
“It's putting too much strain on Jill,” said one top Biden adviser, who spoke on the condition of anonymity to discuss the family dynamic. But as long as Biden wants to run, the advisers say, Jill will support him.
“When Joe gets knocked down, he gets up,” she told donors in New York, “and that's what we're doing today.”