Washington (AFP) - Joe Biden's age has long been his political Achilles' heel -- but a bombshell special counsel investigation has gifted his opponents a ready-made election year attack line by suggesting he couldn't even remember when his son died.
Furious and emotional, the 81-year-old struck back in a televised speech from the White House that underscored both the personal hurt and the political danger that the Democrat faces from an issue he can do little about.
Republicans have pounced on the report by Special Counsel Robert Hur, which while clearing Biden of hoarding classified documents also tarred the president as an "elderly man with a poor memory."
The issue also handily distracts from the fact that 77-year-old Donald Trump -- the Republican former president who's likely to face Biden in a rematch in November and regularly mocks Biden -- has made a few slips of his own.
Biden's age is one of the biggest concerns for US voters. He would be 82 at the start of a second term, and 86 at the end.
After days in which Biden's aides appeared to have largely hidden him from the media, Biden came out fighting on Thursday night during primetime, his voice catching with emotion.
"There's even reference that I don't remember when my son died. How in the hell dare he raise that?" said Biden, whose eldest son Beau died of brain cancer in 2015.
Under fierce questioning by reporters, Biden angrily hit back saying "my memory is fine" and "I know what the hell I'm doing" when asked about his fitness to lead.
But with a long campaign ahead, the issue will only get hotter, said Robert Rowland, professor of political communication at the University of Kansas.
"He's got to satisfy the people that he has the cognitive skills and the strength," Rowland told AFP.
'Gratuitous'
The special counsel report is gold dust for Biden's Republican foes, who swiftly used it to paper over their own chaotic political infighting.
Trump-allied Republican House Speaker Mike Johnson blasted: "A man too incapable of being held accountable for mishandling classified information is certainly unfit for the Oval Office."
Hur, who was appointed by Trump to be US Attorney for the District of Maryland in 2017 before being named by Biden's attorney general Merrick Garland as special counsel, made repeated references to Biden's "diminished faculties."
He added that Biden could not remember the dates of his vice presidency under Barack Obama, and could not remember "even within several years" when his son Beau died.
A political veteran who began his career as a senator in 1972 and endured the tragic death of his wife and baby daughter in a car crash, Biden has long had a reputation for gaffes and word salads.
Those have multiplied in recent years, and together with a number of stumbles and falls that have gone viral on social media, questions have swirled about his readiness for a second term.
The White House pushed back hard against what it called "inaccurate, gratuitous, and wrong" criticisms of Biden's memory.
Even before the special counsel report the White House was already on the back foot, facing repeated questions at a briefing on Thursday over him confusing various European leaders.
On Sunday Biden told a fundraiser that he had spoken to long-dead French president Francois Mitterrand, instead of current leader Emmanuel Macron, at a G7 summit in Britain in June 2021.
Biden told a similar story about the same G7 meeting on Wednesday -- this time saying he had met German Chancellor Helmut Kohl, who died in 2017, instead of Angela Merkel.
Biden, who suffers from a lifelong stammer, also appeared tired while answering questions after a speech on the Mexican border crisis at the White House on Tuesday.
"This happens. It happens to all of us," White House Press Secretary Karine Jean-Pierre said.
Voters don't seem as concerned by Trump's age but he has also had a few recent glitches, such as mixing up his rival for the Republican nomination, Nikki Haley, with former US House speaker Nancy Pelosi.
