By Sam Cabral & Madeline Halpert
BBC News on Capitol Hill & from New York
Democrats are defending President Joe Biden after a report on his handling of classified documents raised concerns about his age and mental fitness.
Mr Biden will not be charged for keeping classified documents, but the report cast him as a "well-meaning, elderly man with a poor memory".
Democratic lawmakers said the description was an inaccurate and unimportant distraction.
Georgia Senator Jon Ossoff dismissed the observation as "just noise".
The youngest member of the Senate told the BBC that special counsel Robert Hur's descriptions of Mr Biden seemed to be an "unusual commentary straying from what one would typically expect in a focused and substantive report".
Mr Biden's legal team had similar concerns, accusing Mr Hur of using language that was not "accurate or appropriate".
Since launching his re-election campaign, Mr Biden has been plagued by concerns about his age and mental capacities. He is 81, just a few years older than the frontrunner Republican candidate, former President Donald Trump, 77.
This report has done little to assuage voters' concerns. It alleged that Mr Biden could not remember when his son Beau died of cancer or when he served as vice president during interviews with investigators.
But Democrats like Mr Ossoff said they remained unconcerned about the president's mental faculties.
Mr Ossoff emphasised that he had spent a "substantial amount of time" with the president in recent months.
"I've found him to be sharp, focused, impressive, formidable and effective," he said.
Mr Ossoff's colleagues agreed, including Senator Chris Van Hollen of Maryland, who called the president "thoughtful and experienced".
Democrats remain "absolutely confident" in the president, he said. "We want to stick with somebody who understands what this country needs."
Other senators in the Capitol on Friday stressed that Mr Hur's remarks appeared to go beyond the scope of the investigation.
"I think it was an entirely inappropriate way to approach the remit of the special counsel and the role of the special counsel," Oregon Senator Jeff Merkley said.
"It's unfortunate it wandered into territory that was so inappropriate."
Minnesota Democrat Tina Smith called Mr Hur's comments on Mr Biden's memory "outrageous" and "despicable".
She accused the Trump appointee of "blatantly politicising" his role as special counsel.
But some of her colleagues across the aisle said Mr Hur's observations just added fuel to the growing perception that Mr Biden was not up to the job of president.
"He's trying to do his best, and his best is beginning to concern me," North Carolina Senator Thom Tillis told the BBC.
"I don't care if you're 78 or 178, if you're going to be the leader of the free world, you've got to be on your game 100 percent," the moderate Republican said.
Concerns about Mr Biden's age are "an enduring problem" for his re-election campaign, Larry Sabato, the director for the Center for Politics at the University of Virginia, told the BBC.
Experts have noted that polling suggests Mr Trump does not face as much criticism from voters about his age, despite having similar gaffes as Mr Biden on the campaign trail.
In recent months, both Mr Biden and Mr Trump have made a series of public errors while publicly speaking, confusing names of world leaders and US politicians on several occasions.
But Mr Trump's bombastic style and "constant offensive posture" may fuel perceptions of him as a more energetic candidate, said Chris Borick, the director of the Muhlenberg College Institute of Public Opinion.
Worries about Mr Trump's age "don't seem to stick in the same way", he said.
But for Mr Biden, his campaign will have to be focused on addressing the perception that he is not mentally fit for office.
"The report adds to the steepness of [Biden's] efforts to overcome what is undoubtedly a significant hindrance to his campaign," Mr Borick said.